Optimized system access procedures

ABSTRACT

A base station subsystem (BSS) and a method are described herein for improving an Access Grant Channel (AGCH) capacity when mobile stations establish an uplink Temporary Block Flow (TBF) triggered by a small data transmission (SDT) or an instant message transmission (IMT). Plus, a mobile station (MS) and a method are described herein for improving the AGCH capacity when the mobile station establishes an uplink TBF triggered by a SDT or an IMT.

CLAIM OF PRIORITY

This application claims the benefit of U.S. Provisional Application Ser.No. 61/535,509 filed on Sep. 16, 2011. Furthermore, this applicationclaims the benefit of U.S. Provisional Application Ser. No. 61/620,696filed on Apr. 5, 2012. The contents of these documents are herebyincorporated by reference herein.

TECHNICAL FIELD

The present invention relates to a base station subsystem (BSS) and amethod for improving an Access Grant Channel (AGCH) capacity when mobilestations establish an uplink Temporary Block Flow (TBF) triggered by asmall data transmission (SDT) or an instant message transmission (IMT).Plus, the present invention relates to a mobile station (MS) and amethod for improving the AGCH capacity when the mobile stationestablishes an uplink TBF triggered by a SDT or an IMT.

BACKGROUND

In the wireless telecommunications field it is anticipated that therewill be an ever increasing Common Control Channel (CCCH) congestionproblem due to the increase of small data transmissions (SDTs) andinstant message transmissions (IMTs) as a result of theMachine-to-Machine (M2M) traffic and the frequent small packettransmissions which are going to be generated by mobile stations (e.g.,smart phones). Various solutions to address the CCCH congestion problemand other problems are the subject of the present invention.

ABBREVIATIONS

The following abbreviations are herewith defined, at least some of whichare referred to within the following description of the presentinvention.

AGCH Access Grant Channel ARFCN Absolute Radio Frequency Channel NumberATI Additional TBF Information BCCH Broadcast Control Channel BSS BaseStation Subsystem CCCH Common Control Channel CS Circuit Switched DRXDiscontinuous Reception EGPRS Enhanced General Packet Radio Service EPCREnhanced Packet Channel Request

eTFI Enhanced Temporary Flow IdentityeUSF Enhanced Uplink State Flag

FN Frame Number IA Incoming Access IE Information Element LAP Low AccessPriority LLC Logical Link Control MAC Media Access Control M2MMachine-to-Machine OSAP Optimized System Access Procedure PACCH PacketAssociated Control Channel PCH Paging Channel PDU Packet Data Unit PFCPacket Flow Context PRR Packet Resource Request PUA Packet UplinkAssignment PUAN Packet Uplink Ack/Nack RF Radio Frequency RLC Radio LinkControl SI System Information TBF Temporary Block Flow TCH TrafficChannel TDMA Time Division Multiple Access TLLI Temporary Logical LinkIdentity TOI Temporary OSAP Identity TSC Training Sequence Code SUMMARY

A base station subsystem (BSS), a mobile terminal (MS) and methods thataddress the aforementioned CCCH congestion problem by improving thecapacity on an AGCH are described in the independent claims of thepresent application. Advantageous embodiments of the BSS, the MS andmethods have been described in the dependent claims of the presentapplication.

In one aspect, the present invention provides a BSS configured tointeract with a plurality of MSs and perform a procedure (e.g., theoptimized system access procedure) to improve an AGCH capacity. The BSScomprises a processor and a memory that stores processor-executableinstructions where the processor interfaces with the memory and executesthe processor-executable instructions to enable a broadcast operation, areceive operation, and a send operation. The broadcast operationincludes broadcasting a new SI to the plurality of MSs, where the new SIincludes an indicator which indicates to the plurality of MSs that theBSS is configured to perform the procedure (e.g., the optimized systemaccess procedure) to improve the AGCH capacity. The receive operationincludes receiving at least one access request from at least one of theplurality of MSs, where the at least one MS is requesting to establishan uplink TBF to transmit a SDT or an IMT (note: the MS would send theaccess request only if the BSS is configured to perform the optimizedsystem access procedure to improve the AGCH capacity). The sendoperation includes sending, in response to the received at least oneaccess request, an immediate assignment message on the AGCH for the atleast one MS, where the immediate assignment message includes staticradio parameters and at least a portion of dynamic radio parameterswhich are to be used along with the static radio parameters by the atleast one MS when establishing the uplink TBF to transmit the SDT orIMT. This is an advantage over the prior art because the BSS bybroadcasting the new SI which includes the new indicator is now able tosend one immediate assignment message to multiple MSs thus improving theAGCH capacity.

In another aspect, the present invention provides a method implementedby a BSS, which interacts with a plurality of MSs, for performing aprocedure (e.g., the optimized system access procedure) to improve anAGCH capacity. The method comprises a broadcasting step, a receivingstep, and a sending step. The broadcasting step includes broadcasting anew SI to the plurality of MSs, where the new SI includes an indicatorwhich indicates to the plurality of MSs that the BSS is configured toperform the procedure (e.g., the optimized system access procedure) toimprove the AGCH capacity. The receiving step includes receiving atleast one access request from at least one of the plurality of MSs,where the at least one MS is requesting to establish an uplink TBF totransmit a SDT or an IMT (note: the MS would send the access requestonly if the BSS is configured to perform the optimized system accessprocedure to improve the AGCH capacity). The sending step includessending, in response to the received at least one access request, animmediate assignment message on the AGCH for the at least one MS, wherethe immediate assignment message includes static radio parameters and atleast a portion of dynamic radio parameters which are to be used alongwith the static radio parameters by the at least one MS whenestablishing the uplink TBF to transmit the SDT or IMT. This is anadvantage over the prior art because the BSS by broadcasting the new SIwhich includes the new indicator is now able to send one immediateassignment message to multiple MSs thus improving the AGCH capacity.

In another aspect, the present invention provides a MS configured tointeract with a BSS and to improve an AGCH capacity. The MS comprising:a processor and a memory that stores processor-executable instructionswhere the processor interfaces with the memory and executes theprocessor-executable instructions to enable a first receiving operation,a sending operation, a second receiving operation, and a usingoperation. The first receiving operation includes receiving a new SIfrom the base station subsystem, where the new SI includes an indicatorwhich indicates to the MS that the BSS is configured to perform aprocedure (e.g., the optimized system access procedure) to improve theAGCH capacity. The sending operation includes sending an access requestto the BSS, where the access request is sent when the MS is requestingto establish an uplink TBF that is triggered by a SDT or an IMT (note:the MS would send the access request 124 only if the BSS 102 isconfigured to perform the optimized system access procedure to improvethe AGCH capacity). The second receiving operation includes receiving animmediate assignment message on the AGCH from the BSS, where theimmediate assignment message includes static radio parameters and atleast a portion of dynamic radio parameters. The using operationincludes using the static radio parameters and the at least a portion ofdynamic radio parameters when establishing the uplink TBF to transmitthe SDT or IMT. This is an advantage over the prior art because the BSSby broadcasting the new SI which includes the new indicator is now ableto send one immediate assignment message to multiple MSs thus improvingthe AGCH capacity.

In another aspect, the present invention provides a method implementedby a MS which interacts with a BSS for improving an AGCH capacity. Themethod comprises a first receiving step, a sending step, a secondreceiving step, and a using step. The first receiving step includesreceiving a new SI from the base station subsystem, where the new SIincludes an indicator which indicates to the MS that the BSS isconfigured to perform a procedure (e.g., the optimized system accessprocedure) to improve the AGCH capacity. The sending step includessending an access request to the BSS, where the access request is sentwhen the MS is requesting to establish an uplink TBF that is triggeredby a SDT or an IMT (note: the MS would send the access request 124 onlyif the BSS 102 is configured to perform the optimized system accessprocedure to improve the AGCH capacity). The second receiving stepincludes receiving an immediate assignment message on the AGCH from theBSS, where the immediate assignment message includes static radioparameters and at least a portion of dynamic radio parameters. The usingstep includes using the static radio parameters and the at least aportion of dynamic radio parameters when establishing the uplink TBF totransmit the SDT or IMT. This is an advantage over the prior art becausethe BSS by broadcasting the new SI which includes the new indicator isnow able to send one immediate assignment message to multiple MSs thusimproving the AGCH capacity.

Additional aspects of the invention will be set forth, in part, in thedetailed description, figures and any claims which follow, and in partwill be derived from the detailed description, or can be learned bypractice of the invention. It is to be understood that both theforegoing general description and the following detailed description areexemplary and explanatory only and are not restrictive of the inventionas disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be obtainedby reference to the following detailed description when taken inconjunction with the accompanying drawings:

FIGS. 1A-1E are several diagrams uses to help explain the wirelesssignaling that occurs between the BSS and multiple MSs to improve thecapacity of the AGCH in accordance with a first embodiment of thepresent invention;

FIGS. 2A-2C are several diagrams uses to help explain the wirelesssignaling that occurs between the BSS and multiple MSs to improve thecapacity of the AGCH in accordance with a second embodiment of thepresent invention;

FIGS. 3A-3C are several diagrams associated with the disclosure in theaforementioned U.S. Provisional Application Ser. No. 61/620,696 whichare used to help explain the wireless signaling that occurs between theBSS and multiple MSs to improve the capacity of the AGCH in accordancewith various embodiments of the present invention; and

FIGS. 4A-4C are several diagrams associated with an article entitled“Detailed OSAP Signalling Procedure” 3GPP TSG-GERAN #54, GP-120624presented by the inventors in Sanya, China, May 14-18, 2012 which areused to further help explain the wireless signaling that occurs betweenthe BSS and multiple MSs to improve the capacity of the AGCH inaccordance with various embodiments of the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1A, there is a diagram illustrating the basic wirelesssignaling that occurs between a BSS 102 and multiple MSs 104 ₁, 104 ₂,104 ₃, 104 ₄ . . . 104 _(n) to improve the capacity of the AGCH 106 inaccordance with a first embodiment of the present invention. As shown,the BSS 102 broadcasts a new SI 120 on the BCCH 122 to the MSs 104 ₁,104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) (step 1). The new SI 120 includes apredetermined set of packet radio resources 134 (i.e., static radioparameters 134) which are to be used by the MSs 104 ₁, 104 ₂, 104 ₃, 104₄ . . . 104 _(n) whenever any one of the MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄. . . 104 _(n) establishes the uplink TBF 128 that is triggered by theSDT 130 a or the IMT 130 b (note: the new SI 120 indicates that the BSS120 is configured to perform an optimized system access procedure toimprove the AGCH capacity). The BSS 102 receives one or more accessrequests 124 on the RACH 126 from one or more MSs 104 ₁ and 104 ₃ (forexample) which now want to transmit the SDT 130 a or the IMT 130 b andare requesting to establish the uplink TBF 128 (step 2) (note: the MSwould send the access request 124 only if the BSS 102 is configured toperform the optimized system access procedure to improve the AGCHcapacity). In response to receiving the access requests 124, the BSS 102sends the immediate assignment message 132 on the AGCH 106 to therequesting MSs 104 ₁ and 104 ₃ (step 3). The immediate assignmentmessage 132 includes at least a portion of the dynamic radio parameters136 which are to be used along with the previously sent static radioparameters 134 by the requesting MSs 104 ₁ and 104 ₃ to establish thecorresponding uplink TBFs 128 and transmit the corresponding SDT 130 aor IMT 130 b (step 4). If only one MS 104 ₁ (for example) sends anaccess request 124 to the BSS 102 during an allowed access timeinterval, then the BSS 102 could choose to send a legacy immediateassignment message which includes the complete set of dynamic radioparameters 136 to the individual MS 104 ₁ so it can establish the uplinkTBF 128 and transmit the SDT 130 a or IMT 130 b. Or, the BSS 102 couldsend the immediate assignment message 132 to the individual MS 104 ₁ soit can establish the uplink TBF 128 and transmit the SDT 130 a or IMT130 b.

If desired, the BSS 102 does not need to include all of the dynamicradio parameters in the immediate assignment message 132 which areneeded by the MSs 104 ₁ and 104 ₃ to establish the uplink TBFs 128. Inthis case, the BSS 102 would send a remaining portion of the dynamicradio parameters 136′ in a message 138 on a PACCH 140 to the requestingMSs 104 ₁ and 104 ₃ which were addressed by the immediate assignmentmessage 132 (step 5). Furthermore, the BSS 102 could send additionalstatic radio parameters 134′ in the message 138 (or some other PACCHmessage if the remaining dynamic radio parameters 136′ are not sent) onthe PACCH 140 to the requesting MSs 104 ₁ and 104 ₃ addressed by theimmediate assignment message 132 (step 5). Then, the requesting MSs 104₁ and 104 ₃ would use the static radio parameters 134 (and theadditional static radio parameters 134′ if sent), the portion of dynamicradio parameters 136 (included in the immediate assignment message 132),and the remaining portion of the dynamic radio parameters 136′ (if sentin message 138) to establish the corresponding uplink TBFs 128 totransmit the corresponding SDT 130 a or IMT 130 b (step 6). In any case,this process is a marked improvement over the prior art since thetraditional BSS was configured to send an immediate assignment message(which included the needed static and dynamic radio parameters) to onlyone MS at a time rather than being configured as in the presentinvention to send an immediate assignment message 132 to multiple MSs104 ₁ and 104 ₃ (for example) at the same time which improves thecapacity of the AGCH 106. A more detailed discussion is provided nextabout the various features and advantages of the first embodiment of thepresent invention.

The aforementioned basic concept of the first embodiment considered hereis that of allowing for a network to identify a pre-determined set ofpacket radio resources 134 (i.e. default radio resources 134, staticradio parameters 134) that are to be used whenever a MS access request124 is triggered by a SDT 130 a or an IMT 130 b. These default radioresources 134 are identified by including them as a new SI 120 which canindicate a set of one or more static radio parameters 134 that thenetwork would commonly assign when using a legacy packet accessprocedure to assign radio resources appropriate for the MS's SDT or IMTtransmissions. This new SI 120 has the static radio parameters 134 whereeach set of static radio parameters 134 includes a corresponding RadioAssignment Identity (RAID) value (referenced by the enhanced immediateassignment message 132 on the AGCH 106) along with associated parametervalues for the following Information Elements (IEs) (which can currentlybe included within a legacy immediate assignment message):

-   -   Page Mode    -   Packet Channel Description    -   Mobile Allocation    -   Starting Time    -   IA Rest Octets

A network supporting the transmission of static radio parameters 134 aspart of SI 120 should therefore include at least one complete set ofthese parameters. The MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) thatreceives these static radio parameters 134 via SI 120 will not need tobe sent this same information on the AGCH 106 when attempting a systemaccess for an SDT or IMT transmission. As such, this packet radioresource pre-allocation procedure effectively frees up AGCH capacity bymodifying the immediate assignment message 132 to only include thedynamic radio parameters 136 (e.g. timing advance and TFI) (not thestatic radio parameters 134) needed by the requesting MS 104 ₁ and 104 ₃when establishing an uplink TBF 128. The modified immediate assignmentmessage 132 (e.g., enhanced immediate assignment (EIA) message 132)allows for a greater number of MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) to be addressed by any given instance of an EIA message 132 whencompared to a legacy immediate assignment message which can only addressa single MS.

The inclusion of static radio parameters 134 within SI 120 (e.g. usingSI 21) indicates the BSS 102 supports reception of a new RACH burst thatincludes a new training sequence (TS) that the MS 104 ₁ (for example)would send in the access request 124 to indicate that the SDT 130 a orthe IMT 130 has triggered the access attempt. The access request 124will be 11 bits long as per the legacy EGPRS Packet Channel Requestmessage but will use different code points and as such is referred toherein as an Enhanced Packet Channel request message 124 which can (forexample) be coded as shown in TABLE 1:

TABLE 1 Enhanced Packet Channel Request Message 124's content < EnhancedPacket channel request message content > ::= < MO SDT - One Phase AccessRequest : 000 < RandomBits : bit (8) > > | < MO IMT - One Phase AccessRequest : 001 < RandomBits : bit (8) > > | < Paging Response - One PhaseAccess Request : 010 < RandomBits : bit (8) > >;

The exemplary Enhanced Packet Channel request message 124 shown in TABLE1 allows for five additional code points to be defined for anyadditional services for which a high volume of corresponding accessattempts are anticipated and therefore can be better supported using theEnhanced Packet Channel request 124—Enhanced Immediate assignmentmessage 132 signaling exchange described herein (i.e. new code pointscan be defined to support services other than SDT 130 a and IMT 130 b).In addition, this signaling scheme is not limited to being used withinthe context of one phase access attempts but can also be used for twoaccess attempts. The reason that the one phase access case is indicatedin TABLE 1 is that it allows for the minimum amount of control planesignaling to be used in support of SDT 130 a and IMT 130 btransmissions.

The MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) (which is not a legacyMS) that supports the transmission of the enhanced packet channelrequest message 124 must of course be able to read the static radioparameters 134 sent as part of SI 120 before making such an accessrequest 124. The rate at which the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . .104 _(n) is expected to refresh (i.e. re-read) the static radioparameters 134 information is nominally once every 30 seconds (i.e. asper the legacy periodicity for re-reading legacy SI). Note: The PageMode information (proposed for inclusion in the static radio parameters134) is not expected to change often and so allowing for a nominal 30second refresh rate for the static radio parameters 134 (and thereforethe Page Mode) is considered to be acceptable.

It should be noted that the static radio parameters 134 informationincludes the IA Rest Octets which, as currently defined, includes USF,TFI and Request Reference information which is dynamic by its verynature. As such, either a new IA Rest Octets that excludes all dynamicinformation can be defined or the legacy IA Rest Octets can still beused where it is understood that the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . .104 _(n) will simply ignore all dynamic information regardless of whatit is set to.

The BSS 102's reception of an enhanced packet channel request message124 on the RACH 126 indicates that the corresponding MS 104 ₁ (forexample) supports the reception of the enhanced immediate assignmentmessage 132 on the AGCH 106. The BSS 102 can therefore respond to theaccess request 124 by sending the enhanced immediate assignment message132 that includes one instance of the following dynamic radio parameters136 for each MS 104 ₁ and 104 ₃ (for example) addressed by this message:

-   -   RAID corresponding to the applicable set of static radio        parameters 134 (2 bits—allows for up to 4 sets of static radio        parameters 134 to be included in the SI 120)    -   Echoed enhanced packet channel request code point (11 bits)—see        Note 1    -   Assigned eTFI (8 bits)—See Note 2 and 3    -   Assigned eUSF (8 bits)—See Note 2 and 3    -   Timing Advance (8 bits)—See Note 4    -   FN Information (16 bits)—See Note 5

Note 1: This information overrides the 11 bit access request code pointvalue if provided when the IA Rest Octets IE is sent as part of thestatic radio parameters 134.

Note 2: This assumes the set of static radio parameters 134 indicated byRAID is only used for the MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)that support RLC/MAC enhancements (i.e. having an RLC/MAC protocol thatsupports 8 bit TFI and USF values means backward compatibility will notbe supported on these packet radio resources).

Note 3: It may be acceptable to leave eUSF information out of theenhanced immediate assignment message 132 if the BSS 102, after sendingthe MS 104 ₁ (for example) the enhanced immediate assignment message132, waits for it to move to the assigned packet radio resource and thensends it a new PACCH message 138 containing the eUSF information 136′.In other words, if eUSF information 136 is missing from the enhancedimmediate assignment message 132 then the MS 104 ₁ (for example) willwait to receive the eUSF information 136′ in a new RLC/MAC controlmessage 138 sent on the PACCH 140 before it can make any uplinktransmissions on the allocated packet radio resource. Similarly, theenhanced immediate assignment message 132 can include a legacy TFI value(5 bits) instead of an eTFI value (8 bits) in which case the MS 104 ₁(for example) will use the legacy TFI value until it receives an eTFIassignment 136′ in the new RLC/MAC control message 138 sent on the PACCH140. Whenever PACCH signaling is used to supplement the dynamic radioparameters 136 sent with the enhanced immediate assignment message 132then the MS 104 ₁ (for example) must receive this RLC/MAC controlmessage 138 before it can proceed to complete contention resolution asper the legacy one phase (or two phase) access procedure.

Note 4: It may be acceptable to leave Timing Advance information 136 outof the enhanced immediate assignment message 132 if the BSS 102, aftersending the MS 104 ₁ (for example) the enhanced immediate assignmentmessage 132, waits for it to move to the assigned packet radio resourceand then sends it a RLC/MAC control message 138 on the PACCH 140containing the Timing Advance information 136′. In other words, ifTiming Advance information is missing from the enhanced immediateassignment message 132, then the MS 104 ₁ (for example) will wait toreceive this information on the PACCH 140 before it can make any uplinktransmissions on the allocated packet radio resource.

Note 5: With an 8 bit “RandomBits” field included in the enhanced packetchannel request message 124 (see TABLE 1) the need for the enhancedimmediate assignment message 132 to include any FN related info may beeliminated (i.e. for the case of access collision between two or moreMSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) all possible ambiguitywill of course be cleaned up when contention resolution is completed buthaving an 8 bit “RandomBits” field can be viewed as being sufficient toensure an acceptably low probability of having multiple MSs 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) still in contention after the enhancedpacket channel request message 124 (RACH 126)—enhanced immediateassignment message 132 (AGCH 106) exchange. Alternatively, some portionof the FN (frame number) can be carried within the legacy RequestReference IE and could be included such as T1′ (see FIG. 1B). Thepurpose of the legacy Request Reference information element is toprovide the random access information used in the access request message124 sent on the RACH 126 and the frame number (FN) modulo 42432 in whichthe access request 124 was received. In this case, the legacy RequestReference information element shown in FIG. 1B would be coded asfollows.

-   -   RA, Random Access Information (octet 2). This is an unformatted        8 bit field. Typically the contents of this field are coded the        same as the CHANNEL REQUEST message shown in FIG. 1C    -   TF (octet 2). The TF field is coded as the binary representation        of (FN div 1326) mod 32.    -   T3 (octet 3 and 4). The T3 field is coded as the binary        representation of FN mod 51. Bit 3 of octet 2 is the most        significant bit and bit 6 of octet 3 is the least significant        bit.    -   T2 (octet 4). The T2 field is coded as the binary representation        of FN mod 26.        NOTE: The frame number, FN modulo 42432 can be calculated as        51×((T3−T2)mod 26)+T3+51×26×T1′

It should be noted that the Extended RA (5 bit field) can be includedwithin the IA Rest Octets IE of the legacy Immediate Assignment (IA)message and has a content consisting of the 5 least significant bits ofthe EGPRS PACKET CHANNEL REQUEST message defined in 3GPP TS 44.060 (thecontents of which are incorporated herein by reference). It is includedfor the case of an 11-bit access request message 124 since the RA fieldof the Request Reference IE (also included within the legacy IA message)in FIG. 1B only provides 8 bits of information and as such the full11-bit access request message can only be echoed to a MS 104 ₁ (forexample) using supplementary information provided by the Extended RA IE.

The dynamic radio parameters 136 described above could be carried withinthe EIA Rest Octets IE of the enhanced immediate assignment message 132as shown below in TABLE 2:

TABLE 2 Enhanced Immediate Assignment message 132 Information IEIelement Type/Reference Presence Format length L2 Pseudo Length L2 PseudoLength M V 1 10.5.2.19 RR management Protocol M V ½ ProtocolDiscriminator Discriminator 10.2 Skip Indicator Skip Indicator M V ½10.3.1 Immediate Message Type M V 1 Assignment 10.4 Message Type EIARest Octets EIA Rest Octets M V 20  10.5.2.xx

The sum of the length of the EIA Rest Octets IE and the L2 Pseudo LengthIE equals 22 (see TABLE 2). The L2 pseudo length is the sum of lengthsof all information elements present in the EIA message 132 except theEIA Rest Octets and L2 Pseudo Length information elements (i.e. 2octets). This leaves 20 octets of space for the EIA Rest Octets whichcan be used to provide dynamic radio parameters 136 for a variablenumber of MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) as follows:

EIA Capacity Gain Case 1:

In this case all of the dynamic radio parameters 136 described above areincluded for each MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressedby the EIA Rest Octets IE. This translates into 6 octets+5 bits peraddressed MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) which thereforeallows for 3 distinct MSs to be addressed by each instance of theenhanced immediate assignment message 132 which results in a three-foldincrease in the capacity of the AGCH 106 when compared to using thelegacy immediate assignment message (which provides radio resources forone MS).

EIA Capacity Gain Case 2:

In this case only a subset of the dynamic radio parameters 136 describedabove are included for each MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)addressed by the EIA Rest Octets IE as follows:

-   -   RAID corresponding to the applicable set of SDT Radio Parameters        134 (2 bits)    -   Echoed enhanced packet channel request code point (11 bits)    -   Assigned eTFI (8 bits)

This translates into 2 octets+5 bits per addressed MS 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) which allows for six distinct MSs to beaddressed by each instance of the enhanced immediate assignment message132 which results in a six-fold increase in the capacity of the AGCH 106when compared to using the legacy immediate assignment message (whichprovides radio resources for one MS).

EIA Capacity Gain Case 3:

In this case only a subset of the dynamic radio parameters 136 describedabove are included for each MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)addressed by the EIA Rest Octets IE as follows:

-   -   RAID corresponding to the applicable set of SDT Radio Parameters        134 (2 bits)    -   Echoed enhanced packet channel request code point (11 bits)    -   Assigned Legacy TFI (5 bits)

This translates into 2 octets+2 bits per addressed MS 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) which allows for eight distinct MSs to beaddressed by each instance of the enhanced immediate assignment message132 which results in an eight-fold increase in the capacity of the AGCH106 when compared to using the legacy immediate assignment message(which provides radio resources for one MS).

EIA Capacity Gain Case 4:

In this case only a subset of the dynamic radio parameters 136 describedabove are included for each MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)addressed by the EIA Rest Octets IE as follows:

-   -   RAID corresponding to the applicable set of SDT Radio Parameters        134 (2 bits)    -   Echoed enhanced packet channel request code point (11 bits)

A single instance of an eTFI (8 bits) is also included in the enhancedimmediate assignment message 132 which the first addressed MS willconsider as its assigned eTFI value. The 2^(nd) addressed MS willconsider eTFI+1 as its assigned eTFI value and the 3^(rd) addressed MSwill consider eTFI+2 as its assigned eTFI etc. . . .

This translates into 1 octet+5 bits per addressed MS+one instance of the8 bit eTFI value which allows for 11 distinct MSs to be addressed byeach instance of the enhanced immediate assignment message 132 whichresults in an eleven-fold increase in the capacity of the AGCH 106 whencompared to using the legacy immediate assignment message (whichprovides radio resources for one MS).

It should be noted that following contention resolution the BSS 102 canchoose to use PACCH signaling 138 to send a MS 104 ₁, 104 ₂, 104 ₃, 104₄ . . . 104 _(n) one or more additional sets of static radio parameters134′. The BSS 102 can then refer to these static radio parameters 134′using RAID in subsequent enhanced immediate assignment messages it sendsto that MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n). This thereforeallows the BSS 102 to maintain MS specific static radio parameters 134′which may be of interest for certain classes of MSs (e.g. for stationaryMSs) which may allow for minimizing the amount of SI 120 bandwidth usedto convey static radio parameters 134. For example, only a single set ofstatic radio parameters 134 may need to be included as part of SI 120 ifthe PACCH 140 is used to supplement this information as needed forspecific subsets of MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n).

Referring to FIG. 1D, there is a flowchart of an exemplary method 100 dimplemented by the BSS 102 which is configured to interact with multipleMSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) and perform a procedure toimprove the capacity of the AGCH 106 in accordance with the firstembodiment of the present invention. The BSS 102 includes the processor110 and the memory 112 that stores processor-executable instructionswhere the processor 110 interfaces with the memory 112 and executes theprocessor-executable instructions to perform method 100 d's steps asdiscussed next. At step 102 d, the BSS 102 broadcasts the new SI 120 onthe BCCH 122 to the MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n). Thenew SI 120 includes a predetermined set of packet radio resources 134(i.e., static radio parameters 134) which are to be used by the MSs 104₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) whenever any one of the MSs 104 ₁,104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) establishes the uplink TBF 128 thatis triggered by the SDT 130 a or the IMT 130 b. At step 104 d, the BSS102 receives one or more access requests 124 (within an allowed (i.e.restricted) access time interval) on the RACH 126 from one or more MSs104 ₁ and 104 ₃ (for example) which now want to transmit the SDT 130 aor the IMT 130 b and are requesting to establish the uplink TBF 128. Inresponse to receiving the access requests 124, the BSS 102 at step 206 dsends the immediate assignment message 132 on the AGCH 106 for therequesting MSs 104 ₁ and 104 ₃. The immediate assignment message 132includes at least a portion of the dynamic radio parameters 136 whichare to be used along with the static radio parameters 134 by therequesting MSs 104 ₁ and 104 ₃ (for example) when establishing thecorresponding uplink TBFs 128 to transmit the corresponding SDT 130 a orIMT 130 b. In the event, the BSS 102 does not include all of the dynamicradio parameters in the immediate assignment message 132 sent duringstep 106 d which are needed by the requesting MSs 104 ₁ and 104 ₃ toestablish the uplink TBFs 128, then the BSS 102 at step 108 d could senda remaining portion of the dynamic radio parameters 136′ in a message138 on a PACCH 140 to the requesting MSs 104 ₁ and 104 ₃. If desired,the BSS 102 at step 110 d could send additional static radio parameters134′ in the message 138 (or some other message if the remaining dynamicradio parameters 136′ are not sent) on the PACCH 140 to the MSs 104 ₁and 104 ₃. Then, the MSs 104 ₁ and 104 ₃ would use the static radioparameters 134 (and the additional static radio parameters 134′ ifsent), the portion of dynamic radio parameters 136 (included in theimmediate assignment message 132), and the remaining portion of thedynamic radio parameters 136′ (if sent in message 138) to establish thecorresponding uplink TBFs 128 to transmit the corresponding SDT 130 a orIMT 130 b.

Referring to FIG. 1E, there is a flowchart of an exemplary method 100 eimplemented by MS 104 ₁ (for example) which is configured to interactwith the BSS 102 and to improve the capacity of the AGCH 106 inaccordance with the first embodiment of the present invention. The MS104 ₁ includes the processor 116 and the memory 118 that storesprocessor-executable instructions where the processor 116 interfaceswith the memory 118 and executes the processor-executable instructionsto perform method 100 e's steps as discussed next. At step 102 e, the MS104 ₁ receives the new SI 120 on the BCCH 122 from the BSS 102. The newSI 120 includes a predetermined set of packet radio resources 134 (i.e.,static radio parameters 134) which are to be used by the MS 104 ₁ whenestablishing the uplink TBF 128 that is triggered by the SDT 130 a orthe IMT 130 b. At step 104 e, the MS 104 ₁ sends the access request 124on the RACH 126 when requesting to establish the uplink TBF 128 that istriggered by the SDT 130 a or the IMT 130 b. At step 106 e, the MS 104 ₁receives the immediate assignment message 132 on the AGCH 106 from theBSS 102. The immediate assignment message 132 includes at least aportion of the dynamic radio parameters 136 which are to be used alongwith the static radio parameters 134 by the MS 104 ₁ when establishingthe corresponding uplink TBFs 128 to transmit the corresponding SDT 130a or IMT 130 b. In the event, the BSS 102 does not include all of thedynamic radio parameters in the immediate assignment message 132 whichare needed by the MS 104 ₁ to establish the uplink TBFs 128, then the MS104 ₁ at step 108 e would receive a remaining portion of the dynamicradio parameters 136′ in a message 138 on a PACCH 140 from the BSS 102.Furthermore, the MS 104 ₁ at step 110 e could receive additional staticradio parameters 134′ in the message 138 (or some other message if theremaining dynamic radio parameters 136′ are not sent) on the PACCH 140from the BSS 102. At step 112 e, the MS 104 ₁ would use the static radioparameters 134 (and the additional static radio parameters 134′ ifsent), the portion of dynamic radio parameters 136 (included in theimmediate assignment message 132), and the remaining portion of thedynamic radio parameters 136′ (if sent in message 138) to establish theuplink TBF 128 to transmit the SDT 130 a or IMT 130 b.

Referring to FIG. 2A, there is a diagram illustrating the basic wirelesssignaling that occurs between the BSS 102 and the MSs 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) (multiple MSs 104 shown) to improve the capacityof the AGCH 106 in accordance with the second embodiment of the presentinvention. As shown, the BSS 102 broadcasts a new SI 120 on the BCCH 122to the MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) (step 1). The newSI 120 includes an indicator 302 which indicates to the MSs 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) that the BSS 102 is configured to performthe optimized system access procedure to improve the capacity of theAGCH 106. The content of the new SI 120 can be limited to providing thissingle indicator 302 if suitable static radio parameters 134 areprovided by either the legacy SI 13 message or by the immediateassignment message 132. The BSS 102 receives one or more access requests124 on the RACH 126 from one or more MSs 104 ₁ and 104 ₃ (for example)which now want to transmit the SDT 130 a or the IMT 130 b and arerequesting to establish the uplink TBF 128 (step 2) (note: the MS wouldsend the access request 124 only if the BSS 102 is configured to performthe optimized system access procedure to improve the AGCH capacity). Inresponse to receiving the access requests 124, the BSS 102 sends theimmediate assignment message 132 on the AGCH 106 to the requesting MSs104 ₁ and 104 ₃ (step 3). The immediate assignment message 132 includesa predetermined set of packet radio resources 134 (i.e., static radioparameters 134—same as the ones described in the first embodiment), andat least a portion of the dynamic radio parameters 136 (same asdescribed in the first embodiment) both of which are to be used by therequesting MSs 104 ₁ and 104 ₃ when establishing the correspondinguplink TBFs 128 to transmit the corresponding SDT 130 a or IMT 130 b(step 4). If only one MS 104 ₁ (for example) sends an access request 124to the BSS 102 during an allowed access time interval, then the BSS 102could choose to send a legacy immediate assignment message whichincludes the static radio parameters 134 and the dynamic radioparameters 136 to the individual MS 104 ₁ so it can establish the uplinkTBF 128 and transmit the SDT 130 a or IMT 130 b. Or, the BSS 102 couldsend the immediate assignment message 132 to the individual MS 104 ₁ soit can establish the uplink TBF 128 and transmit the SDT 130 a or IMT130 b.

If desired, the BSS 102 does not need to include all of the dynamicradio parameters in the immediate assignment message 132 which areneeded by the requesting MSs 104 ₁ and 104 ₃ to establish the uplinkTBFs 128. In this case, the BSS 102 would send a remaining portion ofthe dynamic radio parameters 136′ in a message 138 on a PACCH 140 to therequesting MSs 104 ₁ and 104 ₃ which were addressed by the immediateassignment message 132 (step 5). Furthermore, the BSS 102 could sendadditional static radio parameters 134′ in the message 138 (or someother message if the remaining dynamic radio parameters 136′ are notsent) on the PACCH 140 to the requesting MSs 104 ₁ and 104 ₃ (step 5).Then, the requesting MSs 104 ₁ and 104 ₃ would use the static radioparameters 134 (and the additional static radio parameters 134′ ifsent), the portion of dynamic radio parameters 136 (included in theimmediate assignment message 132), and the remaining portion of thedynamic radio parameters 136′ (if sent in message 138) to establish thecorresponding uplink TBFs 128 to transmit the corresponding SDT 130 a orIMT 130 b (step 6). In any case, this process is a marked improvementover the prior art since the traditional BSS was configured to send animmediate assignment message to only one MS at a time rather than beingconfigured as in the present invention to send an immediate assignmentmessage 132 to multiple MSs 104 ₁ and 104 ₃ (for example) at the sametime which improves the capacity of the AGCH 106.

Referring to FIG. 2B, there is a flowchart of an exemplary method 200 bimplemented by the BSS 102 which is configured to interact with multipleMSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) and perform a procedure toimprove the capacity of the AGCH 106 in accordance with the secondembodiment of the present invention. The BSS 102 includes the processor110 and the memory 112 that stores processor-executable instructionswhere the processor 110 interfaces with the memory 112 and executes theprocessor-executable instructions to perform method 200 b's steps asdiscussed next. At step 202 b, the BSS 102 broadcasts the new SI 120 onthe BCCH 122 to the MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n). Thenew SI 120 includes an indicator 302 which indicates to the MSs 104 ₁,104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) that the BSS 102 is configured toperform the procedure to improve the capacity of the AGCH 106. At step204 b, the BSS 102 receives one or more access requests 124 (within anallowed (i.e. restricted) access time interval) on the RACH 126 from oneor more MSs 104 ₁ and 104 ₃ (for example) which now want to transmit theSDT 130 a or the IMT 130 b and are requesting to establish the uplinkTBF 128. In response to receiving the access requests 124, the BSS 102at step 206 b sends the immediate assignment message 132 on the AGCH 106for the requesting MSs 104 ₁ and 104 ₃. The immediate assignment message132 includes a predetermined set of packet radio resources 134 (i.e.,static radio parameters 134—same as the ones described in the firstembodiment), and at least a portion of the dynamic radio parameters 136(same as described in the first embodiment) both of which are to be usedby the requesting MSs 104 ₁ and 104 ₃ when establishing thecorresponding uplink TBFs 128 to transmit the corresponding SDT 130 a orIMT 130 b. In the event, the BSS 102 does not include all of the dynamicradio parameters in the immediate assignment message 132 which areneeded by the requesting MSs 104 ₁ and 104 ₃ to establish the uplinkTBFs 128, then the BSS 102 at step 208 b would send a remaining portionof the dynamic radio parameters 136′ in a message 138 on a PACCH 140 tothe requesting MSs 104 ₁ and 104 ₃. If desired, the BSS 102 at step 210b could send additional static radio parameters 134′ in the message 138(or some other message if the remaining dynamic radio parameters 136′are not sent) on the PACCH 140 to the requesting MSs 104 ₁ and 104 ₃.Then, the requesting MSs 104 ₁ and 104 ₃ would use the static radioparameters 134 (and the additional static radio parameters 134′ ifsent), the portion of dynamic radio parameters 136 (included in theimmediate assignment message 132), and the remaining portion of thedynamic radio parameters 136′ (if sent in message 138) to establish thecorresponding uplink TBFs 128 to transmit the corresponding SDT 130 a orIMT 130 b.

Referring to FIG. 2C, there is a flowchart of an exemplary method 200 cimplemented by MS 104 ₁ (for example) which is configured to interactwith the BSS 102 and to improve the capacity of the AGCH 106 inaccordance with the second embodiment of the present invention. The MS104 ₁ includes the processor 116 and the memory 118 that storesprocessor-executable instructions where the processor 116 interfaceswith the memory 118 and executes the processor-executable instructionsto perform method 200 c's steps as discussed next. At step 202 c, the MS104 ₁ receives the new SI 120 on the BCCH 122 from the BSS 102. The newSI 120 includes an indicator 302 which indicates to the MSs 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) that the BSS 102 is configured to performthe procedure to improve the capacity of the AGCH 106. At step 204 c,the MS 104 ₁ sends the access request 124 on the RACH 126 whenrequesting to establish the uplink TBF 128 that is triggered by the SDT130 a or the IMT 130 b. At step 206 c, the MS 104 ₁ receives theimmediate assignment message 132 on the AGCH 106 from the BSS 102. Theimmediate assignment message 132 includes a predetermined set of packetradio resources 134 (i.e., static radio parameters 134—same as the onesdescribed in the first embodiment), and at least a portion of thedynamic radio parameters 136 (same as described in the first embodiment)both of which are to be used by the requesting MSs 104 ₁ and 104 ₃ whenestablishing the corresponding uplink TBFs 128 to transmit thecorresponding SDT 130 a or IMT 130 b. In the event, the BSS 102 does notinclude all of the dynamic radio parameters in the immediate assignmentmessage 132 which are needed by the requesting MS 104 ₁ to establish theuplink TBFs 128, then the MS 104 ₁ at step 208 c would receive aremaining portion of the dynamic radio parameters 136′ in a message 138on a PACCH 140 from the BSS 102. Furthermore, the MS 104 ₁ at step 210 ccould receive additional static radio parameters 134′ in the message 138(or some other message if the remaining dynamic radio parameters 136′are not sent) on the PACCH 140 from the BSS 102. At step 212 c, the MS104 ₁ would use the static radio parameters 134 (and the additionalstatic radio parameters 134′ if sent), the portion of dynamic radioparameters 136 (included in the immediate assignment message 132), andthe remaining portion of the dynamic radio parameters 136′ (if sent inmessage 138) to establish the uplink TBF 128 to transmit the SDT 130 aor IMT 130 b.

The following detailed discussion describes various features andadvantages associated with the present invention. In particular, thefollowing detailed discussion is based on the disclosure in theaforementioned U.S. Provisional Application Serial No. 61/620,696 filedon Apr. 5, 2012. In addition, the underlined portions below highlightdifferences between the disclosure of U.S. Provisional Application Ser.No. 61/620,696 and an article prepared by the inventors entitled“Optimized System Access Procedure” 3GPP TSG-GERAN #54, GP-120623 andpresented in Sanya, China, May 14-18, 2012. Finally, reference numeralshave been added to the disclosure of U.S. Provisional Application Ser.No. 61/620,696.

“OSAP Assisted Downlink TBF Establishment” Abstract

In light of increasing CCCH congestion problems anticipated as a resultof M2M traffic and frequent small packet transmissions 130 a and 130 bgenerated by smart phones 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) anenhanced procedure for PS domain triggered system access referred to asOptimized System Access Procedure (OSAP) is considered herein. The keyobjective of OSAP is to increase AGCH 106 capacity by minimizing thesize of the MS specific information carried within AGCH based assignmentmessages 132. This can be accomplished by offloading the transmission ofcertain radio parameters 134 to system information 120, limiting thecontent 136 of the assignment messages 132 to what is strictly necessaryto direct a MS104 ₁ to a packet resource and using the PACCH 140 of thepacket resource to assign the MS 104 ₁ any remaining information 134′and 136′ it requires for uplink TBF 128 establishment. A detailedevaluation of OSAP shows that it can provide up to an eight-fold gaincompared to legacy AGCH operation wherein a legacy Immediate Assignmentmessage is assumed to assign packet resources for a single MS.

1. Introduction

Discussion of mechanisms for improving AGCH 106 capacity has beenongoing for a number of GERAN meetings with possible solutions asdescribed in references [1] and [2]. A reasonable operational example toconsider that provides motivation for the OSAP feature described hereinis as follows:

-   -   The 51-multiframe format of a downlink CCCH could, for a given        period of high system load, consist of an average of 4 PCH        blocks and 5 AGCH blocks (i.e. in addition to the radio block        used for BCCH Norm).    -   For a single instance of this 51-multiframe format there would        be 51 RACH bursts resulting in a RACH burst to AGCH block ratio        of about 10 to 1 (reduced to about 5 to 1 when factoring in the        degradation of RACH performance due to collisions inherent to        slotted aloha operation) which strongly suggests the AGCH will        be a bottleneck.    -   Using IPA as a means to mitigate this imbalance results in        achieving a 10 to 3 ratio (i.e. since IPA allows for up to 3 MS        to be addressed by a single assignment message) but further        mitigation of this imbalance is desirable if feasible (note: IPA        is an alternative to OSAP and is discussed in reference [1] and        later below).    -   For DL TBF establishment when a MS is in READY STATE, the IPA        feature provides no performance increase as DL TBFs will always        be established using the legacy Immediate Assignment message.

The OSAP feature described herein allows for further reducing the RACHburst to AGCH block ratio as follows:

-   -   Allowing for the inclusion of Mobile Allocation information 134        as new system information (SI) 120 to identify the subset of        ARFCNs defined by the Cell Allocation to be used when frequency        hopping is used in a given cell. The Mobile Allocation        information 134 included as SI 120 can be referred to as “Static        Radio Parameters” (SRP) 134 and would apply to packet resources        assigned to mobile stations 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104        _(n) using OSAP.    -   Limiting the content of AGCH based assignment messages 132 to        what is strictly necessary to direct a mobile station 104 ₁ to a        packet resource where it waits for a downlink PACCH message 138.    -   Sending a PACCH message 138 on the downlink of the assigned        packet resource to provide a MS 104 ₁ with all additional        information 134′ and 136′ needed to complete the establishment        of either an uplink TBF 128 or downlink TBF.    -   Introducing a new AGCH message 132 referred to as an Enhanced        Immediate Assignment (EIA) message 132 and a new PACCH message        138 referred to as an Additional TBF Information (ATI) message        138.

FIG. 3A shows an example according to the first embodiment of thepresent invention of how the content of 5 legacy IA messages 402 can beeffectively distributed within (a) system information 120, (b) a singleEIA message 132 and (c) a single instance of an ATI message 138 (i.e.whereby a RACH burst to AGCH block ratio of 10 to 5 is realized).Additional analysis within this discussion paper shows that a single EIAmessage 132 can be used to address up to 8 different MSs 104 ₁, 104 ₂,104 ₃, 104 ₄ . . . 104 _(n) thereby allowing for a 10 to 8 ratio to berealized using OSAP.

2. Optimized System Access Procedure—Overview

The SRP information 134 can be carried within SI 120 (e.g. using SI 21)(according to the first embodiment of the present invention). Or, the SI120 will at minimum provide an indication 302 (according to the secondembodiment of the present invention). In any case, the SI 120 indicateswhen a serving cell supports the Optimized System Access Procedure(OSAP) wherein the corresponding BSS 102 is capable of receiving a newRACH burst 124 that involves the use of a new training sequence code(TSC). The reception of an access request message 124 known as anEnhanced Packet Channel Request 124 (EPCR) sent using this new TSCallows for introducing new OSAP specific code points in the 11-bit EPCRmessage as per TABLE 3 below.

TABLE 3 ENHANCED PACKET CHANNEL REQUEST 124 message content < EnhancedPacket channel request message content > ::= < OSAP Request - one phaseaccess : 00 < Priority : bit (2) > < MultislotClassGroup : bit (3) > <RandomBits : bit (4) > > < OSAP Request - signalling :  01000  <Priority : bit (2) > < RandomBits : bit (4) > > < OSAP Request - singleblock packet access : 01001 < Priority : bit (2) > < RandomBits : bit(4) > > < OSAP Request - two phase access : 01010 < Priority : bit (2) >< RandomBits : bit (4) > >;

The basic signaling events associated with an OSAP based system accessfor uplink TBF 128 establishment wherein a one phase access is used areshown in FIG. 3B.

3. Analysis of the Legacy Immediate Assignment Message Content

The content of the legacy Immediate Assignment message is examined belowon a per information element basis to identify which information muststill be included within the OSAP specific EIA message 132 sent on theAGCH 106 and which information can be sent later using one or more OSAPspecific ATI message 138 instances sent on the PACCH 140 (i.e. thatsupplements the packet resource information provided by the OSAPspecific assignment message 132).

TABLE 4 Legacy IMMEDIATE ASSIGNMENT message content IEI Informationelement Type/Reference Presence Format length L2 Pseudo Length L2 PseudoLength M V 1 10.5.2.19 RR management Protocol Protocol Discriminator M V½ Discriminator 10.2 Skip Indicator Skip Indicator M V ½ 10.3.1Immediate Assignment Message Type M V 1 Message Type 10.4 Page Mode PageMode M V ½ 10.5.2.26 Dedicated mode or TBF Dedicated mode or TBF M V ½10.5.2.25b Channel Description Channel Description C V 3 10.5.2.5 PacketChannel Description Packet Channel Description C V 3 10.5.2.25a RequestReference Request Reference M V 3 10.5.2.30 Timing Advance TimingAdvance M V 1 10.5.2.40 Mobile Allocation Mobile Allocation M LV 1-9 10.5.2.21 7C Starting Time Starting Time O TV 3 10.5.2.38 IA Rest OctetsIA Rest Octets M V 0-11 10.5.2.16

-   -   Page Mode: This content of this legacy IE is included within the        Page Mode IE of the EIA message 132 shown in TABLE 6. This IE        allows for informing a MS not addressed by the EIA message 132        about possible extended paging operation and is therefore not        deferrable to an ATI message 124.    -   Dedicated mode or TBF: Not required since the system access        scenario considered herein is always associated with TBF        establishment.    -   Channel Description: Not required since it is associated with        identifying a TCH.    -   Packet Channel Description: An enhanced version of this legacy        IE is included within the Packet Channel Description IE of the        EIA message 132 as shown in TABLE 6 (i.e. the enhanced version        consists of the legacy IE with the Channel type field and the        spare bits removed). This IE provides the basic amount of        information required by a mobile station 104 ₁ to identify the        assigned packet resources and is therefore not deferrable to an        ATI message 138.    -   Request Reference: An enhanced version of this legacy IE is        included in the EIA message 132 where similar information is        carried using the MS Specific EIA Parameters IE as shown in        TABLE 6. This information is used for the purpose of contention        resolution and is therefore not deferrable to an ATI message        138.    -   Timing Advance: Included in an ATI message 138 instance sent on        the PACCH 140.    -   Mobile Allocation: Can be included in the SRP information 134        sent on BCCH 122 or included in the EIA message 132. If        frequency hopping is applied, the mobile station 104 ₁ uses the        last Cell Allocation received on S11 to decode the Mobile        Allocation.    -   Starting Time: Included in an ATI message 138 instance sent on        the PACCH 140.    -   IA Rest Octets: An enhanced version of this legacy IE is        included in an ATI message 138 instance where similar        information is carried using the MS Specific TBF Parameters IE        as shown in TABLE 7 (i.e. the enhanced version of this legacy IE        eliminates the CSN.1 extension mechanism used for indicating        information on a per release basis).

4. SRP Information Content

The SRP information 134 can be carried within SI 120 (e.g. using SI 21)(according to the first embodiment of the present invention). Or, the SI120 will at minimum provide an indication 302 (according to the secondembodiment of the present invention). In any case, the SI 120 indicatesthat a serving cell supports OSAP based system access and MobileAllocation information (optional). If frequency hopping is used then theMobile Allocation information indicates the subset of RF channelsbelonging to the Cell Allocation used in the frequency hopping sequence.

-   -   A maximum of 8 octets is needed to include SRP information 134        within an SI message 120 (i.e. a cell allocation can at most        consist of 64 ARFCNs).    -   When SRP 134 information or the indicator 302 is included within        an SI message 120 a single instance of OSAP Mobile Allocation        information is seen as being sufficient for the packet radio        resources that can be assigned using the OSAP procedure.    -   For example, the following structure could be added as a Rel-12        extension to the SI 21 message 120.

{0 | 1 -- OSAP based system access procedure supported { 0 -- OSAPMobile Allocation not included as part of system information | 1 <Number of Octets : bit (3) > { < OSAP Mobile Allocation : bit (8) > } *(val(Number of Octets)+1) } } ;Each bit of each OSAP Mobile Allocation octet corresponds to a specificfrequency in the Cell Allocation frequency list as currently describedfor the legacy Mobile Allocation information element.

5. Enhanced Immediate Assignment (EIA) Message 132 Content

This message 132 is formatted as shown in TABLE 5 below and is sent onthe AGCH 106 by the network to provide mobile stations 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) with a minimum amount of packet resourceinformation 134 (i.e. as a result of receiving this information a MS 104₁ can only receive PACCH messages 138 on the packet resources assignedby the EIA message 132 and must therefore wait until it receivesadditional TBF related information 134′ and 136′ on the PACCH 138 beforean uplink TBF 128 can be used for payload transmission or payload can bereceived on a downlink TBF).

TABLE 5 ENHANCED IMMEDIATE ASSIGNMENT message 132 content InformationIEI element Type/Reference Presence Format length L2 Pseudo Length L2Pseudo M V 1 Length 10.5.2.19 RR management Protocol M V ½ ProtocolDiscriminator Discriminator 10.2 Skip Indicator Skip Indicator M V ½10.3.1 Enhanced Message Type M V 1 Immediate 10.4 Assignment MessageType EIA Rest Octets EIA Rest M V 1 . . . 20 Octets 10.5.2.xx

The length (in octets) of all information provided by the EIA RestOctets IE and the value provided by the L2 Pseudo Length IE has amaximum value of 22 (see TABLE 5 above). The L2 pseudo length indicatesthe sum of the lengths of all information elements present in the EIAmessage 132 except the EIA Rest Octets IE and the L2 Pseudo Length IEitself and as such has a value of 2. This leaves a maximum of 20 octets(160 bits) of space available for the EIA Rest Octets IE.

One instance of the EIA Rest Octets IE is included per EIA message 132and consists of the fields shown in TABLE 6 below where these fields areused as follows:

-   -   Page Mode (2 bits): One instance is included per EIA message        132.    -   Implicit Reject CS (1 bit): One instance is included per EIA        message 132. Note that this is included so that an OSAP capable        MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) configured for LAP        can detect an Implicit Reject for the CS domain when it happens        to read an EIA message 132 on the AGCH 106 while attempting a        non-OSAP system access for the CS domain.    -   Implicit Reject PS (1 bit): One instance is included per EIA        message 132. Note that this is included so that an OSAP capable        MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) configured for LAP        can detect an Implicit Reject for the PS domain when it reads an        EIA message 132 on the AGCH 106 that does not provide matching        FN Information+Random Bits.    -   Message Reference ID (2 bits): One instance is included per EIA        message 132. This information is included so that a MS 104 ₁,        104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) can compare the value of the        Message Reference ID received in a subsequent ATI message 138        instance against the value received in the EIA message 132 and        thereby verify when it has received an ATI message 138 instance        that supplements a previously received EIA message 132.    -   Packet Channel Description (18 or 19): One instance is included        per EIA message 132 (i.e. it is common to all MSs 104 ₁, 104 ₂,        104 ₃, 104 ₄ . . . 104 _(n) addressed by the EIA message 132)        and its content is the same as per the legacy Packet Channel        Description IE (see TABLE 6 below).    -   Mobile Allocation (1, 11, 19, 27 or 35): One instance may be        included per EIA message 132 (i.e. when included it is common to        all MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by        the EIA message 132) and it is limited to providing 32 bits        Mobile Allocation information. If more than 32 bits of Mobile        Allocation information are needed or Mobile Allocation        information is sent using system information 120 (i.e. SRP 134)        then this information is not included in the EIA message 132.    -   FN Information Length (2 bits): One instance is included per EIA        message 132 and allows for 4 different lengths of FN Information        to be indicated.    -   Temporary OSAP Identity Length (2 bits): One instance is        included per EIA message 132 and allows for 4 different lengths        of Temporary OSAP Identity to be indicated.    -   FN Information (Z bits=val(FN Information Length)+9): One        instance is included per MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104        _(n) addressed by the EIA message 132 for the purpose of uplink        TBF 128 establishment.        -   FN Information=the binary value of ‘FN modulo X’ where            FN=the TDMA frame number of the burst in which an Enhanced            Packet Channel Request 124 was received on the RACH 126 by            the BSS 102.        -   X can be set to reflect an acceptable probability for TDMA            frame number collision. For example, for X=256 (Z=8 bits)            the time between uplink bursts for which FN mod 256 has the            same value is 1.18 sec (i.e. each TDMA frame=4.615 ms,            256*4.615=1.18).        -   This means there will be some degree of uncertainty on            behalf of mobile stations 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . .            104 _(n) regarding whether or not matching ‘FN Information’            they receive in an EIA message 132 really reflects the            specific burst in which they sent their access request            message on the RACH 126.        -   The length of the MS specific FN information (Z bits)            included in an EIA message 132 is variable allowing for            operators to increase/decrease the probability of TDMA FN            collision to a level they are comfortable with.    -   Random Bits (4 bits): One instance is included per MS 104 ₁, 104        ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by the EIA message 132        and has a corresponding instance of the FN Information field        (i.e. corresponding instances of FN Information and Random Bits        sent in an EIA message 132 are a reflection of the “Z” least        significant bits of the TDMA FN and Random Bits received by the        BSS 102 within an earlier EPCR message 124).    -   Temporary OSAP Identity (Y bits=val(Temporary OSAP Identity        Length)+9): One instance is included per MS 104 ₁, 104 ₂, 104 ₃,        104 ₄ . . . 104 _(n) addressed by the EIA message 132 for the        purpose of downlink TBF establishment. It allows for an HA        message 132 to identify each mobile station 104 ₁, 104 ₂, 104 ₃,        104 ₄ . . . 104 _(n) based on its specific Temporary OSAP        Identity. If a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) has        not been assigned a Temporary OSAP Identity then legacy        procedures are used for downlink TBF establishment.

TABLE 6 EIA Rest Octets Information Element <EIA Rest Octets > ::= <Page Mode : bit (2) > < Implicit Reject CS : bit > < Implicit Reject PS: bit > < Message Reference ID : bit (2) > < Packet Channel Description: < Packet Channel Description struct > > { 0 | 1 < Mobile AllocationLength : bit (2) > < Mobile Allocation : bit (8 * ( val(MobileAllocation Length) + 1)) > } < FN Information Length : bit (2) > <Temporary OSAP Identity Length : bit (2) > { 1 < MS Specific EIAParameters : < MS Specific EIA Parameters struct > > } ** 0 <sparepadding> ; < Packet Channel Description struct> ::= < TN : bit (3) > <TSC : bit (3) > { 0 { 0 < ARFCN : bit (10) > -- non-hopping RF channelconfiguraion | 1 < MAIO : bit (6) > -- indirect encoding of hopping RFchannel configuration < MA_NUMBER_IND : bit > { 0 | 1 < CHANGE_MARK_1 :bit (2) > } } | 1 < MAIO : bit (6) > -- direct encoding of hopping RFchannel configuration < HSN : bit (6) > }; < MS Specific EIA Parametersstruct> ::= { 0 < FN Information : bit (val(FN Information Length) +9) > < Random Bits : bit (4) > | 1 < Temporary OSAP Identity : bit(val(Temporary OSAP Identity Length) + 9)> } ;

EIA Example 1 The EIA message 132 is used only for the case of uplinkTBF 128 establishment where FN Information provided for each MS 104 ₁,104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by the EIA message 132 is 9bits long (i.e. Z=9, X=512). In this case all MS 104 ₁, 104 ₂, 104 ₃,104 ₄ . . . 104 _(n) making access requests 124 within a TDMA framewhere the 9 least significant bits of that TDMA frame matches the FNInformation sent in the EIA message 132 will then look at thecorresponding Random Bits field to determine if they have received aresponse that matches their access request 124. Note that in this casethe TDMA frames having the same 9 least significant bits will be amultiple of 2.36 sec apart (i.e. 512*4.615 ms=2.36 s).

-   -   The EIA message 132 content specific to each addressed MS=FN        Information (9)+Random Bits (4)+MS ID Discriminator (1)=14 bits.    -   The EIA message 132 content for which a single instance is        included (regardless of how many MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ .        . . 104 _(n) are addressed)=Page Mode (2)+Implicit Reject CS        (1)+Implicit Reject PS (1)+Message Reference ID (2)+Packet        Channel Description (19)+Mobile Allocation (1)+FN Information        Length (2)+Temporary OSAP Identity Length (2)=30 bits.    -   The maximum number of MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104        _(n) addressed per EIA message 132=8 (i.e. 8*14+30=142).    -   According to TABLE 6 above 10 bits of CSN.1 overhead are        required for the EIA message 132 (1 bit to indicate no mobile        allocation is included, 1 bit for each of the 8 instances of the        MS Specific EIA Parameters IE included in the message and 1 bit        to indicate the “direct encoding of hopping RF channel        configuration” is used).    -   The resulting EIA message 132 has a total length of 152 bits.

EIA Example 2

This example builds on EIA example 1 above except that it allows for 10bits of FN Information (i.e. Z=10, X=1024) for each MS 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) addressed by the EIA message 132. In this caseall MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) making access requests124 within a TDMA frame where the 10 least significant bits of that TDMAframe matches the FN Information sent in the EIA message 132 will thenlook at the corresponding Random Bits field to determine they havereceived a response that matches their access request 124. Note that inthis case the TDMA frames having the same 10 least significant bits willbe a multiple of 4.72 sec apart (i.e. 1024*4.615 ms=4.72 s).

-   -   The EIA message 132 content specific to each addressed MS=FN        Information (10)+Random Bits (4)+MS ID Discriminator (1)=15        bits.    -   The EIA message 132 content for which a single instance is        included (regardless of how many MS are addressed)=Page Mode        (2)+Implicit Reject CS (1)+Implicit Reject PS (1)+Message        Reference ID (2)+Packet Channel Description (19)+Mobile        Allocation (1)+FN Information Length (2)+Temporary OSAP Identity        Length (2)=30 bits.    -   The maximum number of MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104        _(n) addressed per EIA message 132=8 (i.e. 8*15+30=150).    -   According to TABLE 6 above 10 bits of CSN.1 overhead are        required for the EIA message 132 (1 bit to indicate no mobile        allocation is included, 1 bit for each of the 8 instances of the        MS Specific EIA Parameters IE included in the message and 1 bit        to indicate the “direct encoding of hopping RF channel        configuration” is used).    -   The resulting EIA message 132 has a total length of 160 bits.

EIA Example 3

This example builds on example 2 above except that it allows for 24 bitsof Mobile Allocation information to be included within the EIA message132.

-   -   The EIA message 132 content specific to each addressed MS=FN        Information (10)+Random Bits (4)+MS ID Discriminator (1)=15        bits.    -   The EIA message 132 content for which a single instance is        included (regardless of how many MS are addressed)=Page Mode        (2)+Implicit Reject CS (1)+Implicit Reject PS (1)+Message        Reference ID (2)+Packet Channel Description (19)+Mobile        Allocation (27)+FN Information Length (2)+Temporary OSAP        Identity Length (2)=56 bits.    -   The maximum number of MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104        _(n) addressed per EIA message 132=6 (i.e. 6*15+56=146).    -   According to TABLE 6 above 8 bits of CSN.1 overhead are required        for the EIA message 132 (1 bit to indicate a mobile allocation        is included, 1 bit for each of the 6 instances of the MS        Specific EIA Parameters IE included in the message and 1 bit to        indicate the “direct encoding of hopping RF channel        configuration” is used).    -   The resulting EIA message 132 has a total length of 154 bits

6. Additional TBF Information (ATI) Message 138 Content

This message 138 is formatted as shown in TABLE 7 below and is sent onthe PACCH 140 by the network to provide mobile stations 104 ₁, 104 ₂,104 ₃, 104 ₄ . . . 104 _(n) with additional information 134′ and 136′required for uplink TBF 128 or downlink TBF establishment. A set of oneor more ATI message 138 instances can be sent by the BSS 102 where eachinstance in the set corresponds to the same EIA message 132 and iscarried within a single PACCH block. This will minimize the amount ofinformation any given MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)addressed by a given EIA message 132 must receive within the EIA message132. Note that until a MS receives an ATI message 138 instancecontaining information that supplements the information it previouslyreceived in an EIA message 132 it can only receive on the downlink PACCH140 the packet resources assigned by the EIA message 132. The content ofthis message 138 consists of the following:

-   -   MS Specific TBF Parameters (X bits): One instance is included        per MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by an        ATI message 138.    -   Page Mode (2 bits): One instance is included per ATI message        138.    -   Message Reference ID (2 bits): One instance is included per ATI        message 138. This information is included so that a MS 104 ₁,        104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) can compare it to the value        in the previously received EIA message 132 and thereby verify        when it has received an ATI message 138 that corresponds to the        EIA message 132 in which it detected matching FN Information and        Random Bits.    -   MS Assignment Bitmap (8 bits): One instance is included per ATI        message 138. This bitmap indicates which subset of MS addressed        by a given EIA message 132 are assigned resources by a received        ATI message 138. Depending on the amount of MS specific        information required, multiple ATI messages 138 corresponding to        the same EIA message 132 can be sent. The net result is that the        “Nth” MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by        an EIA message 132 will only have to correctly receive one        corresponding ATI message 132 instance (i.e. the ATI message        instance having a MS Assignment Bitmap with a “1” in bit        position “N”). For example, if we assume that 5 MS 104 ₁, 104 ₂,        104 ₃, 104 ₄, 104 ₅ are addressed in a given EIA message 132        then 2 corresponding ATI message 138 instances can be sent where        ATI message instance 1 addresses MS1, MS2 and MS3 and ATI        message instance 2 addresses MS4 and MS5 as per FIG. 3C. Thus        any combination of up to 8 MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . .        104 _(n) can be addressed in the set of ATI message 138        instances corresponding to the same EIA message 132.

The number of MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed bythe MS Specific TBF Parameters IE included in a given ATI message 138instance can therefore be a subset of the total number of MS 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by the MS Specific EIAParameters IE included in the EIA Rest Octets IE (see TABLE 6) carriedwithin the corresponding EIA message 132. The ordering of MS addressedby the MS Specific TBF Parameters IE included in a given ATI message 138instance will therefore be determined by the MS Assignment Bitmap IE.

TABLE 7 Additional TBF Information (ATI) Message 138 < Additional TBFInformation message content > ::= < PAGE_MODE : bit (2) > < MessageReference ID : bit (2) > < MS Assignment Bitmap : bit (8) > { 1 < MSSpecific TBF Parameters : < MS Specific TBF Parameters struct > > } ** 0<spare padding>; < MS Specific TBF Parameters struct> ::= { 00 < EGPRSPacket Uplink Assignment > | 01 < Packet Uplink Assignment > | 10 <Packet Downlink Assignment > | 11 - reserved } ; < EGPRS Packet UplinkAssignment > : := { 0 | 1 < Access Technologies Request : AccessTechnologies Request struct > } { 0 -- one phase access indication <TFI_ASSIGNMENT : bit (5) > < POLLING : bit > < USF: bit (3) > <USF_GRANULARITY : bit > { 0 | 1 < P0 : bit (4) > < PR_MODE : bit (1) > }< EGPRS CHANNEL_CODING_COMMAND : < EGPRS Modulation and Coding SchemeIE >> <TLLI_BLOCK_CHANNEL_CODING : bit (1) > { 0 | 1 < BEP_PERIOD2 : bit(4) > } < RESEGMENT : bit (1) > < EGPRS Window Size : < EGPRS WindowSize IE >> -- 5 bits { 0 | 1 < ALPHA : bit (4) > } < GAMMA : bit (5) > {0 | 1 < TIMING_ADVANCE_INDEX : bit (4) > } { 0 | 1 < TBF_STARTING_TIME :bit (16) > } { 0 -- ‘0’ indicates that FANR is not activated | 1 -- ‘1’indicates that FANR is activated { 0 -- SSN-based encoding is selected |1 -- Time-based encoding is selected < REPORTED TIMESLOTS : bit (8) > <TSH : bit (2) > } } | 1 -- An uplink RTTI TBF is assigned < RTTI USFMode : bit(1) > < PDCH PAIR INDICATION: bit(3) > < Additional_USF : bit(3) >*(1−val(RTTI USF MODE)) {0 -- One PDCH Pair assigned | 1 < USF2 :bit(3)> -- Two PDCH Pairs assigned < Additional_USF2 : bit(3) >*(1−val(RTTI USF MODE)) } { 0 -- SSN-based encoding is selected | 1-- Time-based encoding is selected < REPORTED TIMESLOTS : bit (8) > <TSH : bit (2) > } | 1 -- two phase access indication (Multi BlockAllocation) {0 | 1 < ALPHA : bit (4) > } < GAMMA : bit (5) > <TBF_STARTING_TIME : bit (16) > < NUMBER OF RADIO BLOCKS ALLOCATED : bit(2) > { 0 | 1 < P0 : bit (4) > < PR_MODE : bit (1) > } } { 0 | 1 < PFI :bit (7) > } ; <Access Technologies Request struct> ::= -- recursivestructure allows any combination of Access technologies < AccessTechnology Type : bit (4) > { 0 | 1 <Access Technologies Request struct>} ; < Packet Uplink Assignment > ::= { 0 -- one phase access <TFI_ASSIGNMENT : bit (5) > < POLLING : bit > < USF: bit (3) > <USF_GRANULARITY : bit > { 0 | 1 < P0 : bit (4) > PR_MODE : bit (1) > } <CHANNEL_CODING_COMMAND : bit (2) > < TLLI_BLOCK_CHANNEL_CODING : bit > {0 | 1 < ALPHA : bit (4) > } < GAMMA : bit (5) > { 0 | 1 <TIMING_ADVANCE_INDEX : bit (4) > } { 0 | 1 < TBF_STARTING_TIME : bit(16) > } | 1 -- two phase access indication (Single Block Allocation) {0 | 1 < ALPHA : bit (4) > } < GAMMA : bit (5) > < TBF_STARTING_TIME :bit (16) > { L | H < P0 : bit (4) > <PR_MODE : bit (1) > } } { 0 | 1 <PFI : bit (7) > } ; < Packet Downlink Assignment > ::= { 0 | 1 <TFI_ASSIGNMENT : bit (5) > < RLC_MODE : bit > { 0 | 1 ALPHA : bit (4) >} < GAMMA : bit (5) > < POLLING : bit > < TA_VALID : bit (1) > } { 0 | 1< TIMING_ADVANCE_INDEX : bit (4) > } { 0 | 1 <TBF_STARTING_TIME : bit(16) > } { 0 | 1 < P0 : bit (4) > < PR_MODE: bit (1) > } { 0 | 1 --indicates EGPRS TBF mode, see 44.060 < EGPRS Window Size : < EGPRSWindow Size IE >> < LINK_QUALITY_MEASUREMENT_MODE : bit (2) > { 0 | 1 <BEP_PERIOD2 : bit (4) > } } { 0 | 1 PFI : bit (7) > } { 0 | 1 < NPMTransfer Time : bit (5) > } {0 - A downlink BTTI TBF is assigned { 0 --FANR is not activated for the assigned TBF | 1 -- FANR is activated forthe assigned TBF < EVENT_BASED_FANR: bit (1) > } | 1 -- A downlink RTTITBF is assigned < EVENT_BASED_FANR: bit (1) > < PDCH PAIR INDICATION:bit(3) > } < Downlink EGPRS Level: < EGPRS Level IE > > ;

ATI Example 1

In this example a one phase access assignment is considered where all MS104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) are assigned uplink TBF 128resources using the Packet Uplink Assignment IE of TABLE 7 above:

-   -   MS Specific TBF Parameters=1+Packet Uplink Assignment (2)+One        Phase Access (1)+TFI_ASSIGNMENT (5)+POLLING (1)+USF        (3)+USF_GRANULARITY (1)+{1+P0 (4)+PR_MODE        (1)}+CHANNEL_CODING_COMMAND (2)+TLLI_BLOCK_CHANNEL_CODING        (1)+{1+ALPHA (4)}+GAMMA (5)+{1+TIMING_ADVANCE_INDEX        (4)}+{1+TBF_STARTING_TIME (0)}+{1+PFI(7)}=47 bits    -   ATI message 138 instance 1 addresses 3 MS as per FIG. 3C=Page        Mode (2)+Message Reference ID (2)+MS Assignment Bitmap (8)+3*(MS        Specific TBF Parameters)=12+3*(47)=153 bits=1 PACCH block.    -   ATI message 138 instance 2 addresses 2 MS as per FIG. 3C=Page        Mode (2)+Message Reference ID (2)+MS Assignment Bitmap (8)+2*(MS        Specific TBF Parameters)=12+2*(47)=106 bits=1 PACCH block.

ATI Example 2

In this example a two phase access assignment is considered where all MS104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) are assigned uplink TBF 128resources using the Packet Uplink Assignment IE of TABLE 7 above:

-   -   MS Specific TBF Parameters=1+Packet Uplink Assignment (2)+Two        Phase Access (1)+{1+ALPHA (4)}+GAMMA (5)+TBF_STARTING_TIME        (16)+{1+P0 (4)+PR_MODE (1)}+{1+PFI(7)}=44 bits    -   ATI message 138 instance 1 addresses 3 MS as per FIG. 3C=Page        Mode (2)+Message Reference ID (2)+MS Assignment Bitmap (8)+3*(MS        Specific TBF Parameters)=12+3*(44)=144 bits=1 PACCH block.    -   ATI message 138 instance 2 addresses 2 MS as per FIG. 3C=Page        Mode (2)+Message Reference ID (2)+MS Assignment Bitmap (8)+2*(MS        Specific TBF Parameters)=12+2*(44)=100 bits=1 PACCH block.

ATI Example 3

In this example a two phase access assignment is considered where all MS104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) are assigned uplink TBF 128resources using the EGPRS Packet Uplink Assignment IE of TABLE 7 above:

-   -   MS Specific TBF Parameters=1+EGPRS Packet Uplink Assignment        (2)+{1+Access Technologies Request (0)}+Two Phase Access        (1)+{1+ALPHA (4)}+GAMMA (5)+TBF_STARTING_TIME (16)+NUMBER OF        RADIO BLOCKS ALLOCATED (2)+{1+P0(4)+PR_MODE (1)}+{1+PFI(7)}=47        bits    -   ATI message 138 instance 1 addresses 3 MS as per FIG. 3C=Page        Mode (2)+Message Reference ID (2)+MS Assignment Bitmap (8)+3*(MS        Specific TBF Parameters)=12+3*(47)=153 bits=1 PACCH block.    -   ATI message 138 instance 2 addresses 2 MS as per FIG. 3C=Page        Mode (2)+Message Reference ID (2)+MS Assignment Bitmap (8)+2*(MS        Specific TBF Parameters)=12+2*(47)=106 bits=1 PACCH block.

7. Downlink TBF Establishment Using OSAP Messages

Here we consider the case where a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . .104 _(n) in Idle mode can be assigned a downlink TBF without firstperforming the paging procedure (i.e. the Ready timer is running and thenetwork knows the MS location at the cell level). According to legacyoperation, downlink TBF establishment is performed by sending anImmediate Assignment message that includes a Packet Downlink TBFAssignment on its paging group (if in DRX mode) or on any AGCHoccurrence (if in non-DRX mode immediately following TBF release).

When considering an OSAP capable MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) the network has the option of using the EIA 132 and ATI 138messages defined for OSAP to allocate such a MS packet resources for adownlink TBF as follows:

-   -   The network must assign the OSAP capable MS 104 ₁, 104 ₂, 104 ₃,        104 ₄ . . . 104 _(n) an alternate identity (called a Temporary        OSAP Identity) on a per cell basis that remains valid while the        Ready timer is running. This requires a BSS 102 to have        knowledge of the length of the Ready timer which can be realized        in a number of ways (e.g. through the support of PFCs).    -   The BSS 102 can use PACCH 140 signaling to assign a MS 104 ₁,        104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) a Temporary OSAP Identity        (TOI) at any time while a TBF is ongoing for an OSAP capable MS        104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n).    -   Once a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) has been        assigned a TOI then as long as it remains valid it can be        included in an EIA message 132 that includes DL TBF related        information for that MS (see the Temporary OSAP Identity field        in TABLE 6).    -   Since the use of FN Information+Random Bits (for UL TBF 128        establishment) or Temporary OSAP Identity (for DL TBF        establishment) is indicated per instance of MS 104 ₁, 104 ₂, 104        ₃, 104 ₄ . . . 104 _(n) addressed by an EIA message 132, any        given instance of an EIA message can support any combination of        MSs 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) for which either        UL or DL TBF establishment is needed (see FIG. 3D—which shows 5        MSs).    -   The Temporary OSAP Identity can be from 9 to 12 bits in length        allowing for up to a maximum of 4096 such identities to be        maintained per cell.    -   It should be noted that this mechanism for DL TBF establishment        reduces the overall DL CCCH load, thus providing additional CCCH        capacity for non-OSAP mobile stations.

The net benefit of having the OSAP messages also allow for DL TBFestablishment is of course that a single EIA message 132 sent on theAGCH 106 can address up to 8 MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) for which DL TBF establishment is needed. An OSAP capable MS 104 ₁,104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) that has been assigned a TemporaryOSAP Identity will acquire SRP information 134/indicator 302 from SI120, receive an EIA message 132 and a supplemental ATI message 138instance to establish a DL TBF following the same steps used for UL TBF128 establishment except that it is addressed using the Temporary OSAPIdentity in the EIA message 132 (i.e. it cannot be addressed using FNInformation+Random Bits since the RACH 126 is not used during DL TBFestablishment for a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) havinga Temporary OSAP Identity in Idle mode).

8. Conclusion

A mechanism for enhancing AGCH 106 capacity has been described based onintroducing an optimized system access procedure (OSAP) whereby theamount of MS specific information within an assignment message 132 senton the AGCH 106 can be minimized by using new BCCH information and PACCH140 signaling to provide supplemental MS specific information. Asindicated by the examples provided in section 5 above, a significantAGCH 106 capacity gain is possible when using OSAP (e.g. 8 mobilestations 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) can be addressed by asingle assignment message 132 sent on the AGCH 106). The OSAP relatedsignaling used for UL TBF 128 establishment can also be used for DL TBFestablishment for a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) whoselocation is known at the cell level. Thereby the same AGCH 106 capacitygain can be achieved for any combination of UL and DL TBF establishment.Considering that the AGCH 106 capacity is seen as becoming increasinglyproblematic if the load offered by devices supporting delay tolerantapplications increases significantly over the next few years, theintroduction of OSAP as a new GERAN Rel-12 feature as described hereinis seen as being beneficial towards minimizing the potential for theAGCH 106 to become a bottleneck.

REFERENCES

-   [1] GP-111202—Continued discussion for IPA parameters—Huawei    Technologies Co., Ltd.-   [2] GP-111065—Usage of Higher MCSs on CCCH Downlink—Telefon AB LM    Ericsson, ST-Ericsson SA-   [3] GP-111708—Improved AGCH Capacity using Static Radio    Parameters—Telefon AB LM Ericsson, ST-Ericsson SA-   [4] GP-111709—Calculating the Probability of Access    Collision—Telefon AB LM Ericsson, ST-Ericsson SA-   [5] GP-111085—Analysis on Traffic Characteristic of IM Service in    China—CMCC    The references can be found at www.3GPP.org.

The following detailed discussion describes various features andadvantages associated with the present invention. In particular, thefollowing detailed discussion is based on an article prepared by theinventors which is entitled “Detailed OSAP Signalling Procedure” 3GPPTSG-GERAN #54, GP-120624 and was presented by the inventors in Sanya,China, May 14-18, 2012.

Detailed OSAP Signalling Procedures 1. Introduction

The OSAP feature described in a companion discussion paper (theaforementioned GP-120623) involves the introduction of new signalingprocedures for more efficiently establishing both uplink and downlinkTBFs. The detailed signaling procedures associated with the OSAP featureused for establishing uplink and downlink TBFs are examined in greaterdetail herein where it can be seen that this signalling essentiallyconsists of a combination of new signaling combined with legacysignaling as follows:

-   -   New BCCH information 120 that indicates the OSAP feature is        supported by the network and which provides information about        the packet data resources that can be assigned using OSAP based        signaling.    -   A new RACH message 124 that allows a BSS 102 to uniquely        determine that a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) is        requesting OSAP based signaling for uplink TBF 128        establishment.    -   New AGCH and PACCH signaling 132 and 138 supporting the        establishment of uplink and downlink TBFs used for uplink and        downlink user data transmission (e.g. 130 a and 130 b for the        case of uplink data transmission).    -   The legacy one phase and two phase contention resolution        procedure for uplink TBF 128 establishment.    -   Legacy TBF management and release procedures for uplink and        downlink TBFs established using OSAP based signaling.

2. OSAP—Detailed Operation for UL TBF 128 Establishment

A serving cell that supports OSAP based signaling is managed by acorresponding BSS 102 that is capable of receiving a new 11-bit RACHmessage 124 consisting of an access burst that involves the use of a newtraining sequence code (TSC). Upon reading all OSAP related systeminformation, an OSAP capable MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) will use this new TSC along with the signaling procedures shown inFIG. 4A (OSAP Signalling Procedures for UL TBF Establishment-Part 1) andFIG. 4B (OSAP Signalling Procedures for UL TBF Establishment-Part 2)below whenever it has uplink payload to send for the PS domain.

-   -   The structures within the box labeled with the numeral “A” in        FIGS. 4A-4B indicate the use of new procedures and timers        whereas the remaining structures indicate the use of legacy        procedure and timers.    -   The OSAP based signalling described below allows for both one        phase and two phase system access procedures and corresponding        contention resolution as per legacy operation.    -   The code points supported by the new 11-bit RACH message 124        allow for indicating the same basic types of access requests as        can be requested using legacy RACH messages (i.e. “one phase        access”, “two phase access”, “signaling” and “single block        packet access”).    -   OSAP based signaling described below allows a BSS 102 to respond        to a new RACH burst 124 by directing a MS 104 ₁, 104 ₂, 104 ₃,        104 ₄ . . . 104 _(n) to use either a one phase or two phase        system access according to the flexibility supported by legacy        operation.

1) An OSAP capable MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) readsOSAP specific system information 120 once every 30 seconds as per thelegacy SI refresh rate and then enters Idle mode.

2) All PS domain access attempts triggered by a MS 104 ₁, 104 ₂, 104 ₃,104 ₄ . . . 104 _(n) capable of OSAP are subject to using OSAPprocedures whereas all CS domain access attempts triggered by such a MS104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) will be managed using legacyCS domain related procedures. An OSAP capable MS 104 ₁, 104 ₂, 104 ₃,104 ₄ . . . 104 _(n) attempting a PS domain access therefore schedulesand starts sending new RACH bursts referred to as Enhanced PacketChannel Request (EPCR) messages 124 which support 11 bits of payloadspace and a training sequence code (TSC) that allows a BSS 102 touniquely detect reception of an EPCR message 124.

The code points supported by the EPCR message 124 allow for a MS 104 ₁,104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) to indicate “one phase access”, “twophase access”, “signaling” and “single block packet access” as per PSdomain related code points supported by the legacy EGPRS Packet ChannelRequest message (see TABLE 8).

3) After starting the access procedure by transmitting an EPCR message124 the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) starts looking foran Enhanced Immediate Assignment (EIA) message 132 with matching “FNInformation” and “Random Bits”. T3146 (legacy) is only started after themaximum number of EPCR messages 124 have been transmitted.

4) Upon receiving an Enhanced Immediate Assignment (EIA) message 132with matching “FN Information” and “Random Bits” (carried within the MSSpecific EIA Parameters IE) the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) stops T3146 (if running), starts T3226 (new), moves to theindicated PDCH resources and monitors the downlink PACCH 140 for amatching Additional TBF Information (ATI) message 138. Note that thismeans a BSS 102 must respond to an EPCR message 124 by sending an EIAmessage 132 since a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)performing an OSAP based system access will only consider EIA messages132 as potentially containing a matching response.

5) Upon receiving an ATI message 138 instance the MS 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) reads the “MS Assignment Bitmap” therein todetermine if it is addressed by that ATI message instance. In otherwords, if it considered the Nth instance of information carried withinthe MS Specific EIA Parameters IE of the EIA message 132 to containmatching information then it checks to see if the Nth bit of this bitmapis set to “1”. If the Nth bit is set to “1” then the MS 104 ₁, 104 ₂,104 ₃, 104 ₄ . . . 104 _(n) concludes that the corresponding instance ofthe MS Specific TBF Parameters IE in the received ATI message 138provides it with all remaining information 134′ and 136′ needed foruplink TBF 128 establishment including whether or not it is to proceedusing the one phase access or the two phase access procedure (see FIG.4B).

A small Message Reference ID field (2 bits long) is present within boththe EIA message 132 and ATI message 138 so that a MS 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) can precisely associate a received ATI message138 instance to the specific EIA message 132 that has the same MessageID value:

-   -   Note that the EIA message 132 will not include any TFI        information (as it will instead be included in the ATI message        138) and as such a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)        assumes that if it received a match in the Nth instance of the        MS specific information in an EIA message 132 then it is to use        the Nth instance of the MS specific information in the ATI        message 138 corresponding to that EIA message 132.    -   Since an ATI message 138 instance may potentially be missed by a        mobile station 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) (i.e.        even though it is sent using CS-1 coding) a BSS 102 may choose        to make limited pre-emptive re-transmissions of these messages.    -   During times of heavy system access load a BSS 102 may need to        send different sets of one or more ATI message 138 instances        (i.e. each set of one or more ATI message 138 instances is        unique in that it addresses the specific group of mobile        stations 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) addressed by        its corresponding EIA message 132) in relatively quick        succession on the PACCH 140 of a specific packet resource while        also making use of pre-emptive ATI message re-transmissions.    -   As such, to avoid the potential for a MS 104 ₁, 104 ₂, 104 ₃,        104 ₄ . . . 104 _(n) to incorrectly associate an ATI message 138        instance with a previously received EIA message 132 (and thereby        apply incorrect additional TBF information), the introduction of        a two bit Message Reference ID field in both the EIA and ATI        messages 132 and 138 is seen as being sufficient.

6) If T3146 expires prior to receiving a matching EIA message 132 orT3226 expires before receiving a matching ATI message 138 then the MS104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) aborts the packet accessattempt and returns to Idle mode.

7) If the ATI message 138 indicates a one phase access is to be used theMS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) stops T3226, starts T3164and waits for the first instance of its assigned USF. Upon receiving thefirst instance of its assigned USF, the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ .. . 104 _(n) stops T3164, sends its first RLC data block and proceedswith one phase access contention resolution according to legacyprocedures. Note that even if a MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) indicates a one phase within an EPCR message 124 (see TABLE 8) theBSS 102 can still send an ATI message 138 that forces the MS 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) to perform a two phase access (see step10 below).

8) If contention resolution is successful the MS 104 ₁, 104 ₂, 104 ₃,104 ₄ . . . 104 _(n) completes the transmission of its user data (LLCPDU) according to legacy operation. After completing the transmission ofits user data the uplink TBF 128 is released according to legacyprocedures.

9) If T3164 expires before the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) receives the first instance of its assigned USF or it experiencesunsuccessful one phase contention resolution it may either retry thepacket access or abort the uplink TBF 128 as per legacy procedures.

10) If the ATI message 138 indicates a two phase access is to be usedthen the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) stops T3226, sendsa PRR, starts T3168 and waits for a PUA in response to the PRR. Uponreceiving the PUA the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)proceeds with two phase contention resolution according to legacyprocedures.

Note that, similar to legacy operation, if the establishment cause inthe EPCR message 124 indicates a request for a one phase packet accessor signaling the network may send an ATI message 138 that grants eithera one phase access or a two phase access. If a Multi Block allocation isgranted by the ATI message 138 it forces the mobile station 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) to perform a two phase access.

11) If contention resolution is successful the MS 104 ₁, 104 ₂, 104 ₃,104 ₄ . . . 104 _(n) stops 13168, starts T3164 and waits for the firstinstance of its assigned USF. Upon receiving the first instance of itsassigned USF then the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) stopsT3164 and begins transmitting its user data (LLC PDU) according tolegacy operation. After completing the transmission of its user data theTBF 128 is released according to legacy procedures.

12) If T3168 expires before the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) receives a PUA in response to the PRR or T3164 expires before theMS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) receives the first instanceof its assigned USF or it experiences unsuccessful two phase contentionresolution then the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) mayeither retry the packet access or abort the uplink TBF 128 as per legacyprocedures.

TABLE 8 ENHANCED PACKET CHANNEL REQUEST message 124 content < EnhancedPacket channel request message content > ::= < OSAP Request - one phaseaccess : 000 < RandomBits : bit (8) > > < OSAP Request - signalling :001 < RandomBits : bit (8) > > < OSAP Request - single block packetaccess : 010 < RandomBits : bit (8) > > < OSAP Request - two phaseaccess : 011 < RandomBits : bit (8) > >;

2. OSAP—Detailed Operation for DL TBF Establishment

The scenario addressed is where an OSAP capable MS 104 ₁, 104 ₂, 104 ₃,104 ₄ . . . 104 _(n) is in Idle mode and can be assigned a downlink TBFwithout first performing the paging procedure because its correspondingReady timer is running and the network therefore knows the MS locationat the cell level. In this case downlink TBF establishment is performedas shown in FIG. 4C (OSAP Signalling Procedures for DL TBFEstablishment).

1) During an ongoing TBF the BSS 102 may at any time use PACCH 140signaling assign a Temporary OSAP Identity (TOI) to an OSAP capable MS104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n). The assigned TOI remainsvalid for as long as the Ready timer is running and therefore requires aBSS 102 to have knowledge of the length of the Ready timer (e.g. thiscan be realized if PFC procedures are supported by the network).

2) Upon receiving downlink payload (i.e. LLC PDUs) for a MS 104 ₁, 104₂, 104 ₃, 104 ₄ . . . 104 _(n) in Idle mode having a valid TOI the BSS102 initiates downlink TBF establishment by sending an EIA message 132that includes the TOI of that MS (i.e. instead of FN Information+RandomBits):

-   -   If the non-DRX mode feature is not supported (i.e. at TBF        release the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)        immediately enters the DRX mode) the BSS 102 sends the EIA        message 132 on the CCCH of the corresponding serving cell using        any of the radio blocks defined by the paging group of that MS        as defined in 3GPP TS 45.002 (the contents of which are        incorporated herein by reference).    -   If the non-DRX mode feature is supported (i.e. at TBF release        the MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) immediately        enters the non-DRX mode for a period of time determined by the        non-DRX timer) and the BSS 102 determines that the MS 104 ₁, 104        ₂, 104 ₃, 104 ₄ . . . 104 _(n) is in the non-DRX mode it may        send the EIA message 132 on the CCCH of the corresponding        serving cell using any non-BCCH blocks. Otherwise, it sends the        EIA message 132 on the CCCH of the corresponding serving cell        using any of the radio blocks defined by the paging group of        that MS).

3) Upon receiving an Enhanced Immediate Assignment (EIA) message 132with matching TOT (carried within the MS Specific EIA Parameters IE) theMS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) stops the non-DRX timer (ifrunning), starts T3226 (new), moves to the indicated PDCH resources andmonitors the downlink PACCH 140 for a matching Additional TBFInformation (ATI) message 138.

4) Upon receiving an ATI message 138 instance the MS 104 ₁, 104 ₂, 104₃, 104 ₄ . . . 104 _(n) reads the “MS Assignment Bitmap” therein todetermine if it is addressed by that ATI message instance. In otherwords, if it considered the Nth instance of information carried withinthe MS Specific EIA Parameters IE of the EIA message 132 to containmatching information then it checks to see if the Nth bit of this bitmapis set to “1”. If the Nth bit is set to “1” then the MS 104 ₁, 104 ₂,104 ₃, 104 ₄ . . . 104 _(n) concludes that the corresponding instance ofthe MS Specific TBF Parameters IE in the received ATI message 138provides it with all remaining information needed for downlink TBFestablishment.

5) If T3226 expires before receiving a matching ATI message 138 then theMS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n) aborts the downlink TBFestablishment attempt and returns to Idle mode.

4. Conclusion

The detailed operation of the OSAP procedure as described aboveeffectively involves the distribution of uplink TBF 128 specificinformation over the BCCH 122, AGCH 106 and PACCH 140 (as compared tojust the AGCH for legacy operation). This allows the MS specific portionof this distributed information sent on the AGCH 106 to be significantlyreduced compared to legacy operation and an AGCH gain is therebyrealized in that the number of MS 104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104_(n) addressed per OSAP specific AGCH assignment message 132 can besignificantly increased compared to legacy AGCH assignment messages.Considering that AGCH 106 capacity is seen as becoming increasingly moreproblematic as system access load increases (e.g. due to the increasedtraffic load by MTC as well as increased use of instant messaging typeapplications) the introduction of OSAP as a new GERAN Rel-12 feature asdescribed herein is seen as providing an essential AGCH capacityimprovement.

The following discussion describes the various advantages that the OSAPprocedure of the present invention has over the IPA procedure that hasbeen presented by Huawei Technologies Co., Ltd. The first detaileddiscussion is based on an article prepared by the inventors which isentitled “IPA Analysis for Uplink Assignments” 3GPP TSG-GERAN #55,GP-120979 and was presented in Vienna, Austria, Aug. 27-31, 2012. And,the second detailed discussion is based on an article prepared by theinventors which is entitled “IPA Analysis for Downlink Assignments” 3GPPTSG-GERAN #55, GP-120980 and was presented in Vienna, Austria, Aug.27-31, 2012.

IPA Analysis for Uplink Assignments (see GP-120979) 1. Introduction

The IPA feature was included in the Rel-11 GERAN specifications in lightof operator networks that experience a high CCCH load and thus havetypically made use of Multiple CCCH (MCCCH) as a means for dealing withthis load. However, when considering IPA as an alternative mechanism foralleviating high CCCH load for the case of uplink TBF establishment,additional consideration must be given to network scenarios with highload where the use of one phase system access is prioritized.

It is shown in this paper that for the case of one phase access IPA willat best be able to support the assignment of two uplink TBFs, becauseIPA must provide more MS specific information than it does for the caseof a two phase access. As such, the IPA capabilities as indicated byreference [1] have been further considered resulting in the followingfindings:

-   -   For the one phase access case, a maximum of two MS can be        addressed within an IPA message regardless if hopping is used or        not (as opposed to 3 MS being addressable for the non-hopping        case as suggested by reference [1]).    -   For the one or two phase access cases where the Direct Encoding        option is used there is no gain as only one MS can be addressed        within an IPA message (this is not discussed in reference [1]).

2. IPA Message Space Analysis

Considering the 19 octet payload space limitation of the “IPA RestOctets IE” (see Annex A.1 below) and analyzing the proposed content forthis IE for the case of uplink TBF assignments where the BCCH carrier isnot used, the following should be noted:

2.1 One Phase Access

-   -   A best case scenario for IPA message space utilization for the        one phase access case (the IPA Uplink Assignment struct is used)        when no frequency hopping is used in which case the Frequency        Parameters struct provides information on a ARFCN (see        highlighted text in Annex A.2 below). When uplink TBF resources        are assigned for this best case scenario we get the following        bit space utilization:        -   Total bits=1+[N*(1+43)+1]+3+1+(3+2+10)+1+1 where N=the            number of MS addressed by the IPA message → maximum value            for N=2 (total bits=1+[2*44+1]+4+15+2=111 bits).        -   This means only 41 bits of payload space will remain            according to the 152 bit limit which is not enough to            support uplink resource assignments for a 3rd mobile            station.    -   A worst case scenario for IPA message space utilization for the        one phase access case when frequency hopping is used in which        case the Frequency Parameters struct can be provided using        Direct encoding 2 information (see magenta shaded text in Annex        A.2 below). When uplink TBF resources are assigned for this        worst case scenario we get the following bit space utilization:        -   Total bits=1+[N*(1+43)+1]+3+1+(3+2+6+6+4+64)+1+1 where N=the            number of MS addressed by the IPA message → maximum value            for N=1 (total bits=1+[1*44+1]+4+85+2=137 bits).        -   This means only 15 bits of payload space will remain            according to the 152 bit limit which is not enough to            support uplink resource assignments for a 2nd mobile            station.

2.2 Two Phase Access

-   -   A best case scenario for IPA message space utilization for the        two phase access case (the IPA Single Block Uplink Assignment        struct is used) is where the Frequency Parameters struct        provides ARFCN information (see highlighted text in Annex A.2        below). When uplink TBF resources are assigned for this best        case scenario we get the following bit space utilization:        -   Total bits=1+1+[N (1+36)+1]+3+1+(3+2+10) where N=the number            of MS addressed by the IPA message → maximum value for N=3            (total bits=2+[3*37+1]+4+15=133 bits).        -   This means only 19 bits of payload space will remain            according to the 152 bit limit which is not enough to            support uplink resource assignments for a 4th mobile            station.    -   A worst case scenario for IPA message space utilization for the        two phase access case is where the Frequency Parameters struct        provides the Direct encoding 2 information (see bold text in        Annex A.2 below). When uplink TBF resources are assigned for        this worst case scenario we get the following bit space        utilization:        -   Total bits=1+1+[N*(1+36)+1]+3+1+(3+2+6+6+4+64) where N=the            number of MS addressed by the IPA message → maximum value            for N=1 (total bits=2+[1*37+1]+4+85=129 bits).        -   This means only 23 bits of payload space will remain            according to the 152 bit limit which is not enough to            support uplink resource assignments for a 2nd mobile            station.

2.3 Baseband Frequency Hopping Used

-   -   A common deployment scenario is where baseband frequency hopping        is used and the BCCH frequency is within the hopping set in        which case the Frequency Parameters IE needs to be included        since MAIO and HSN type information will be needed by a mobile        station. For this scenario, when the Frequency Parameters IE        provides this information using either the Direct Encoding 1 or        Direct Encoding 2 option the worst case scenarios identified in        2.1 and 2.2 above will apply. However, when the Frequency        Parameters IE provides this information using the Indirect        Encoding option the best case scenarios identified in 2.1 and        2.2 above will apply.

2.4 Baseband Frequency Hopping not Used

-   -   Another deployment scenario may be that where baseband hopping        is not used and the BCCH carrier is not preferred for PS        resource allocations (e.g. due to the reduced efficiency of PDCH        resource utilization resulting from non-contiguous PDCHs when        MCCCH is used on the BCCH carrier or when SDCCHs are allocated        on the BCCH carrier). This will require ARFCN information to be        provided by the Frequency Parameters IE which corresponds to the        best case scenarios identified in 2.1 and 2.2 above.

2.5 Implicit Reject Information

-   -   Though not currently specified, the “IPA Rest Octets IE” needs        to include a bit for indicating “Implicit Reject CS” and a bit        for indicating “Implicit Reject PS” since the IPA message can be        sent on the AGCH and should therefore be able to convey implicit        reject information for IPA capable mobile stations. Adding these        2 bits will make the IPA Rest Octets bit shortage problem even        worse.

3. Conclusion

When considering the case of system operation where IPA is used as analternative mechanism for alleviating high CCCH load, even if the bestcase scenario of IPA message space utilization is considered, IPA willonly be able to support the assignment of uplink TBFs for a maximum of 2mobile stations when the use of one phase access is prioritized. Assuch, the use of the IPA feature may in practice only provide a verylimited improvement in AGCH signalling capacity regarding uplink TBFassignments which may not be sufficient for longer term AGCH loadingscenarios.

REFERENCES

-   [1] GP-110616, “Further discussion on IPA message”, source Huawei    Technologies Co. Ltd, Qualcomm Incorporated. GERAN#50.

The reference can be found at www.3GPP.org.

Annex A.1 9.1.18a Immediate Packet Assignment

This message is sent on the CCCH by the network to multiple mobilestations in idle mode to assign either an uplink or a downlink packetdata channel configuration in the cell. See table 9.

The L2 pseudo length of this message is the sum of lengths of allinformation elements present in the message except the IPA Rest Octetsand L2 Pseudo Length information elements.

-   -   NOTE: The network should take into account limitations of        certain mobile stations to understand IMMEDIATE PACKET        ASSIGNMENT message as these mobile stations may not be able to        decode the Page Mode information element.    -   Message type: IMMEDIATE PACKET ASSIGNMENT    -   Significance: dual    -   Direction: network to mobile station

TABLE 9 IMMEDIATE PACKET ASSIGNMENT message content Information IEIelement Type/Reference Presence Format length L2 Pseudo Length L2 PseudoLength M V 1 10.5.2.19 RR management Protocol M V ½ ProtocolDiscriminator Discriminator 10.2 Skip Indicator Skip Indicator M V ½103.1 Immediate Message Type M V 1 Assignment 10.4 Message Type PageMode Page Mode M V ½ 10.5.2.26 Spare Spare M V ½ IPA Rest Octets IPARest Octets M V 19  10.5.2.78

Annex A.2 10.5.2.78 IPA Rest Octets

The IPA Rest Octets information element contains spare bits and possiblyat least one of the IPA Uplink Assignment struct, the IPA DownlinkAssignment struct, and the IPA Single Block Uplink Assignment struct.

The IPA Rest Octets information element is coded according to the syntaxspecified below and described in table 10.

The IPA Rest Octets information element is a type 5 information elementwith 0-19 octets length.

TABLE 10 IPA Rest Octet information element <IPA Rest Octets> ::= { 0 |1 < IPA Uplink Assignment struct >} { 0 | 1 < IPA Downlink Assignmentstruct >} { 0 | 1 < IPA Single Block Uplink Assignment struct >} <sparepadding>; <IPA Uplink Assignment struct> : := {1 < Random Reference :bit (11) > < FN_OFFSET: bit (8) > < GAMMA : bit (5) > <TIMING_ADVANCE_VALUE : bit (6) > < TFI_ASSIGNMENT : bit (5) > < USF: bit(3) > < EGPRS_CHANNEL_CODING_COMMAND : bit (4) > < Radio AccessCapabilities Request: bit (1) > } ** 0; --Repeated as many times asnecessary, once for each addressed device < TN : bit (3) > { 0 ; --‘0’indicates that BCCH frequency shall be used | 1 {< Frequency Parameters:Frequency Parameters struct >} } <IPA Single Block Uplink Assignmentstruct> ::= { 1 < Random Reference : bit (11) > < FN_OFFSET: bit (8) > <GAMMA : bit (5) > < TIMING_ADVANCE_VALUE : bit (6) > <STARTING_TIME_OFFSET: bit (6) >, } ** 0; --Repeated as many times asnecessary, limited by the space in the message < TN : bit (3) > { 0 ;--‘0’ indicates that BCCH frequency shall be used | 1 {< FrequencyParameters: Frequency Parameters struct >} } < Frequency Parametersstruct > ::= < TSC : bit (3) > { 00 < ARFCN : bit (10) > | 01 < Indirectencoding : < Indirect encoding struct > > | 10 < Direct encoding 1 : <Direct encoding 1 struct > > | 11 < Direct encoding 2 : < Directencoding 2 struct > > } ; < Indirect encoding struct > ::= < MAIO : bit(6) > < MA_NUMBER : bit (4) > { 0 | 1 < CHANGE_MARK_1 : bit (2) > { 0 |1 < CHANGE_MARK_2 : bit (2) > } } ; < Direct encoding 1 struct > ::= <MAIO : bit (6) > < GPRS Mobile Allocation : < GPRS Mobile AllocationIE > > ; < Direct encoding 2 struct > ::= < MAIO : bit (6) > < HSN : bit(6) > < Length of MA Frequency List contents : bit (4) > < MA FrequencyList contents : octet (val(Length of MA Frequency List contents) + 3) >; < GPRS Mobile Allocation IE > ::= < HSN : bit (6) > { 0 | 1 < RFLnumber list : < RFL number list struct > > } {0 < MA_LENGTH : bit (6) >< MA_BITMAP : bit (val(MA_LENGTH) + 1) > | 1 { 0 | 1 < ARFCN index list: < ARFCN index list struct > > } } ; < RFL number list struct > ::= <RFL_NUMBER : bit (4) > { 0 | 1 < RFL number list struct > } ; < ARFCNindex list struct > ::= < ARFCN_INDEX : bit (6) > { 0 | 1 < ARFCN indexlist struct > } ;

IPA Analysis for Downlink Assignments (see GP-120980) 1. Introduction

The IPA feature was included in the Rel-11 GERAN specifications in lightof operator networks that experience a high CCCH load and thus havetypically made use of Multiple CCCH (MCCCH) as a means for dealing withthis load. However, when considering IPA as an alternative mechanism foralleviating high CCCH load for the case of downlink TBF establishment,IPA will at best be able to support the assignment of downlink TBFs for2 mobile stations using the “IPA Downlink Assignment struct”. As such,the IPA capabilities as indicated by reference [1] have been furtherconsidered resulting in the following findings:

-   -   When the Direct Encoding option is used for IPA there is no gain        as only one MS can be addressed within an IPA message (this is        not discussed by reference [1]).

2. IPA Message Space Analysis

Considering the 19 octet payload space limitation of the “IPA RestOctets IE” (see Annex A.1 below) and analyzing the proposed content forthis IE for the case of downlink TBF assignments where the BCCH carrieris not used, the following should be noted:

-   -   A best case scenario for IPA message space utilization is where        the Frequency Parameters strict provides ARFCN information (see        highlighted text in Annex A.2 below). When downlink TBF        resources are assigned for this best case scenario we get the        following bit space utilization:        -   Total bits=1+[N*(1+49)+1]+1+1+3+1+(3+2+10)+1 where N=the            number of MS addressed by the IPA message → maximum value            for N=2 (total bits=1+[2*50+1]+6+15+1=124 bits).        -   This means only 28 bits of payload space will remain            according to the 152 bit limit which is not enough to            support downlink resource assignments for a 3rd mobile            station.    -   A worst case scenario for IPA message space utilization is where        the Frequency Parameters struct provides the Direct encoding 2        information (see bold text in Annex A.2 below). When downlink        TBF resources are assigned for this worst case scenario (64 bits        of Mobile Allocation information provided) we get the following        bit space utilization:        -   Total bits=1+[N*(1+49)+1]+1+1+3+1+(3+2+6+6+4+64)+1 where            N=the number of MS addressed by the IPA message → maximum            value for N=1 (total bits=1+[1*50+1]+6+85+1=144 bits).        -   This means only 8 bits of payload space will remain            according to the 152 bit limit which is not enough to            support downlink resource assignments for a 2nd mobile            station.        -   It should also be noted that the Direct encoding 2 struct            allows for more than 64 bits of Mobile Allocation            information in which case an IPA message will not even be            able to assign downlink TBF resources for even 1 mobile            station.    -   A common deployment scenario is where baseband frequency hopping        is used and the BCCH frequency is within the hopping set in        which case the Frequency Parameters IE needs to be included        since MAIO and HSN type information will be needed by a mobile        station. For this scenario, when the Frequency Parameters IE        provides this information using either the Direct Encoding 1 or        Direct Encoding 2 option the worst case scenario above will        apply. However, when the Frequency Parameters IE provides this        information using the Indirect Encoding option the best case        scenario above will apply.    -   Another deployment scenario may be that where baseband hopping        is not used and the BCCH carrier is not preferred for PS        resource allocations (e.g. due to the reduced efficiency of PDCH        resource utilization resulting from non-contiguous PDCHs when        MCCCH is used on the BCCH carrier or when SDCCHs are allocated        on the BCCH carrier). This will require ARFCN information to be        provided by the Frequency Parameters IE which corresponds to the        best case scenario above.    -   Though not currently specified, the “IPA Rest Octets IE” needs        to include a bit for indicating “Implicit Reject CS” and a bit        for indicating “Implicit Reject PS” since the IPA message can be        sent on the AGCH and should therefore be able to convey implicit        reject information for IPA capable mobile stations. Adding these        2 bits will make the IPA Rest Octets bit shortage problem even        worse.

3. Conclusion

When considering the case of system operation where IPA is used as analternative mechanism for alleviating high CCCH load, even if the bestcase scenario of IPA message space utilization is considered IPA willonly be able to support the assignment of downlink TBFs for a maximum of2 mobile stations. As such, the use of the IPA feature may in practiceonly provide a very limited improvement in AGCH signalling capacityregarding uplink TBF assignments which may not be sufficient for longerterm AGCH loading scenarios.

REFERENCE

-   [1] GP-110616, “Further discussion on IPA message”, source Huawei    Technologies Co. Ltd, Qualcomm Incorporated. GERAN#50.

The reference can be found at www.3GPP.org.

Annex A.1 9.1.18a Immediate Packet Assignment

This message is sent on the CCCH by the network to multiple mobilestations in idle mode to assign either an uplink or a downlink packetdata channel configuration in the cell. See table 11.

The L2 pseudo length of this message is the sum of lengths of allinformation elements present in the message except the IPA Rest Octetsand L2 Pseudo Length information elements.

-   -   NOTE: The network should take into account limitations of        certain mobile stations to understand IMMEDIATE PACKET        ASSIGNMENT message as these mobile stations may not be able to        decode the Page Mode information element.    -   Message type: IMMEDIATE PACKET ASSIGNMENT    -   Significance: dual    -   Direction: network to mobile station

TABLE 11 IMMEDIATE PACKET ASSIGNMENT message content Information IEIelement Type/Reference Presence Format length L2 Pseudo Length L2 PseudoLength M V 1 10.5.2.19 RR management Protocol M V ½ ProtocolDiscriminator Discriminator 10.2 Skip Indicator Skip Indicator M V ½10.3.1 Immediate Message Type M V 1 Assignment 10.4 Message Type PageMode Page Mode M V ½ 10.5.2.26 Spare Spare M V ½ IPA Rest Octets IPARest Octets M V 19  10.5.2.78

Annex A.2 10.5.2.78 IPA Rest Octets

The IPA Rest Octets information element contains spare bits and possiblyat least one of the IPA Uplink Assignment struct, the IPA DownlinkAssignment strut, and the IPA Single Block Uplink Assignment struct.

The IPA Rest Octets information element is coded according to the syntaxspecified below and described in table 12.

The IPA Rest Octets information element is a type 5 information elementwith 0-19 octets length.

TABLE 12 IPA Rest Octet information element <IPA Rest Octets> ::= { 0 |1 < IPA Uplink Assignment struct >} { 0 | 1 < IPA Downlink Assignmentstruct >} { 0 | 1 < IPA Single Block Uplink Assignment struct >} <sparepadding>; < IPA Downlink Assignment struct> ::= { 1 < TLLI : bit (32) >< TFI_ASSIGNMENT : bit (5) > < GAMMA : bit (5) > { 0 |1 <TIMING_ADVANCE_VALUE : bit (6) > } } ** 0; --Repeated as many times asnecessary, limited by the space in the message { 0 | 1 <LINK_QUALITY_MEASUREMENT_MODE: bit (2) > } < RLC_MODE : bit > < TN : bit(3) > { 0 --‘0’ indicates that BCCH frequency shall be used | 1 {<Frequency Parameters: Frequency Parameters struct >} } < FrequencyParameters struct > ::= < TSC : bit (3) > { 00 < ARFCN : bit (10) > | 01< Indirect encoding : < Indirect encoding struct > > | 10 < Directencoding 1 : < Direct encoding 1 struct > > | 11 < Direct encoding 2 : <Direct encoding 2 struct > > } ; < Indirect encoding struct > ::= < MAIO: bit (6) > < MA_NUMBER : bit (4) > { 0 | 1 < CHANGE_MARK_1 : bit (2) >{ 0 | 1 < CHANGE_MARK_2 : bit (2) > } } ; < Direct encoding 1 struct >::= < MAIO : bit (6) > < GPRS Mobile Allocation : < GPRS MobileAllocation IE > > ; < Direct encoding 2 struct > ::= < MAIO : bit (6) >< HSN : bit (6) > < Length of MA Frequency List contents : bit (4) > <MA Frequency List contents : octet (val(Length of MA Frequency Listcontents) + 3) > ; < GPRS Mobile Allocation IE > ::= < HSN : bit (6) > {0 | 1 < RFL number list : < RFL number list struct > > } {0 < MA_LENGTH: bit (6) > < MA_BITMAP : bit (val(MA_LENGTH) + 1) > | 1 { 0 | 1 < ARFCNindex list : < ARFCN index list struct > > } } ; < RFL number liststruct > ::= < RFL_NUMBER : bit (4) > { 0 | 1 < RFL number list struct >} ; < ARFCN index list struct > ::= < ARFCN_INDEX : bit (6) > { 0 | 1 <ARFCN index list struct > } ;

Although multiple embodiments of the present invention have beenillustrated in the accompanying Drawings and described in the foregoingDetailed Description, it should be understood that the invention is notlimited to the disclosed embodiments, but instead is also capable ofnumerous rearrangements, modifications and substitutions withoutdeparting from the present invention that as has been set forth anddefined within the following claims.

1. A base station subsystem (BSS) (102) configured to interact with aplurality of mobile stations (104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n))and perform a procedure to improve an Access Grant Channel (AGCH) (106)capacity, the BSS comprising: a processor (110); and a memory (112) thatstores processor-executable instructions where the processor interfaceswith the memory and executes the processor-executable instructions toenable the following operations: broadcast (202 b) a new systeminformation (SI) (120) to the plurality of mobile stations, where thenew SI includes an indicator (302) which indicates to the plurality ofmobile stations that the BSS is configured to perform the procedure toimprove the AGCH capacity; receive (204 b) at least one access request(124) from at least one of the plurality of mobile stations (104 ₁ and104 ₃), where the at least one mobile station is requesting to establishan uplink Temporary Block Flow (TBF) (128) to transmit a small datatransmission (SDT) (130 a) or an instant message transmission (IMT) (130b); and in response to the received at least one access request, send(206 b) an immediate assignment message (132) on the AGCH for the atleast one mobile station, where the immediate assignment messageincludes static radio parameters (134) and at least a portion of dynamicradio parameters (136) which are to be used along with the static radioparameters by the at least one mobile station when establishing theuplink TBF to transmit the SDT or IMT.
 2. The BSS of claim 1, whereinthe processor further executes the processor-executable instructions tosend (208 b) a remaining portion of the dynamic radio parameters (136′)in a message (138) on a Packet Associated Control Channel (PACCH) (140)to the at least one mobile station addressed by the immediate assignmentmessage, where the remaining portion of the dynamic radio parameters areto be used by the at least one mobile station along with the staticradio parameters and the portion of dynamic radio parameters included inthe immediate assignment message when establishing the uplink TBF totransmit the SDT or IMT.
 3. The BSS of claim 1, further comprising astep of sending (210 b) additional static radio parameters (134′) in amessage (138) on a Packet Associated Control Channel (PACCH) (140) tothe at least one mobile station addressed by the immediate assignmentmessage.
 4. The BSS of claim 1, wherein the static radio parameterscomprise a radio assignment identity (RAID) value along with parametervalues for following information elements (IEs): a page mode; a packetchannel description; a mobile allocation; a starting time; and ImmediateAssignment (IA) rest octets.
 5. The BSS of claim 1, wherein theimmediate assignment message comprises a code point indicating anenhanced immediate assignment (EIA) message that includes an EIA RestOctets Information Element (IE) which contains at least a portion ofdynamic radio parameters for each of the at least one mobile station. 6.The BSS of claim 1, wherein the immediate assignment message furtherincludes a packet channel description for each of the at least onemobile station.
 7. A method (200 b) implemented by a base stationsubsystem (BSS) (102), which interacts with a plurality of mobilestations (104 ₁, 104 ₂, 104 ₃, 104 ₄ . . . 104 _(n)), for performing aprocedure to improve an Access Grant Channel (AGCH) (106) capacity, themethod comprising the steps of: broadcasting (202 b) a new systeminformation (SI) (120) to the plurality of mobile stations, where thenew SI includes an indicator (302) which indicates to the plurality ofmobile stations that the BSS is configured to perform the procedure toimprove the AGCH capacity; receiving (204 b) at least one access request(124) from at least one of the plurality of mobile stations (104 ₁, 104₃), where the at least one mobile station is requesting to establish anuplink Temporary Block Flow, TBF (128), to transmit a small datatransmission, SDT (130 a), or an instant message transmission, IMT (130b); and in response to the received at least one access requests,sending (206 b) an immediate assignment message (132) on the AGCH forthe at least one mobile station, where the immediate assignment messageincludes static radio parameters (134) and at least a portion of dynamicradio parameters (136) which are to be used along with the static radioparameters by the at least one mobile station when establishing theuplink TBF to transmit the SDT or IMT.
 8. The method of claim 7, furthercomprising a step of sending (208 b) a remaining portion of the dynamicradio parameters (136′) in a message (138) on a Packet AssociatedControl Channel (PACCH) (140) to the at least one mobile stationaddressed by the immediate assignment message, where the remainingportion of the dynamic radio parameters are to be used by the at leastone mobile station along with the static radio parameters and theportion of dynamic radio parameters included in the immediate assignmentmessage when establishing the uplink TBF to transmit the SDT or IMT. 9.The method of claim 7, further comprising a step of sending (210 b)additional static radio parameters (134′) in a message (138) on a PacketAssociated Control Channel (PACCH) (140) to the at least one mobilestation addressed by the immediate assignment message.
 10. The method ofclaim 7, wherein the static radio parameters comprise a radio assignmentidentity (RAID) value along with parameter values for followinginformation elements (IEs): a page mode; a packet channel description; amobile allocation; a starting time; and Immediate Assignment (IA) restoctets.
 11. The method of claim 7, wherein the immediate assignmentmessage comprises a code point indicating an enhanced immediateassignment (EIA) message that includes an EIA Rest Octets InformationElement (IE) which contains at least a portion of dynamic radioparameters for each of the at least one mobile station.
 12. The methodof claim 7, wherein the immediate assignment message further includes apacket channel description for each of the at least one mobile station.13. A mobile station (104 ₁) configured to interact with a base stationsubsystem (102) and to improve an Access Grant Channel (AGCH) (106)capacity, the mobile station comprising: a processor (116); and a memory(118) that stores processor-executable instructions where the processorinterfaces with the memory and executes the processor-executableinstructions to enable the following operations: receive (202 c) a newsystem information (SI) (120) from the base station subsystem, where thenew SI includes an indicator (302) which indicates to the mobile stationthat the BSS is configured to perform a procedure to improve the AGCHcapacity; send (204 c) an access request (124) to the base stationsubsystem, where the access request is sent when the mobile station isrequesting to establish an uplink Temporary Block Flow (TBF) (128) thatis triggered by a small data transmission (SDT) (130 a) or an instantmessage transmission (IMT) (130 b); receive (206 c) an immediateassignment message (132) on the AGCH from the base station substation,where the immediate assignment message includes static radio parameters(134) and at least a portion of dynamic radio parameters (136); and use(212 c) the static radio parameters and the at least a portion ofdynamic radio parameters when establishing the uplink TBF to transmitthe SDT or IMT.
 14. The mobile station of claim 13, wherein theprocessor further executes the processor-executable instructions toreceive (208 c) a remaining portion of the dynamic radio parameters(136′) in a message (138) on a Packet Associated Control Channel (PACCH)(140) from the base station subsystem, where the remaining portion ofthe dynamic radio parameters are to be used by the mobile station alongwith the static radio parameters and the portion of dynamic radioparameters received in the immediate assignment message whenestablishing the uplink TBF to transmit the SDT or the IMT.
 15. Themobile station of claim 13, wherein the processor further executes theprocessor-executable instructions to receive (210 c) additional staticradio parameters (134′) in a message (138) on a Packet AssociatedControl Channel (PACCH) (140).
 16. A method (200 c) implemented by amobile station (104 ₁) which interacts with a base station subsystem(102) for improving an Access Grant Channel (AGCH) (106) capacity, themethod comprising the steps of: receiving (202 c) new system information(SI) (120) from the base station subsystem, where the new SI includes anindicator (302) which indicates to the mobile station that the BSS isconfigured to perform a procedure to improve the AGCH capacity; sending(204 c) an access request (124) to the base station subsystem, where theaccess request is sent when the mobile station is requesting toestablish an uplink Temporary Block Flow (TBF) (128) that is triggeredby a small data transmission (SDT) (130 a) or an instant messagetransmission (IMT) (130 b); receiving (206 c) an immediate assignmentmessage (132) on the AGCH from the base station substation, where theimmediate assignment message includes static radio parameters (134) andat least a portion of dynamic radio parameters (136); and using (212 c)the static radio parameters and the at least a portion of dynamic radioparameters when establishing the uplink TBF to transmit the SDT or IMT.17. The method of claim 16, further comprising a step of receiving (208c) a remaining portion of the dynamic radio parameters (136′) in amessage (138) on a Packet Associated Control Channel (PACCH) (140) fromthe base station subsystem, where the remaining portion of the dynamicradio parameters are to be used by the mobile station along with thestatic radio parameters and the portion of dynamic radio parametersreceived in the immediate assignment message when establishing theuplink TBF to transmit the SDT or the IMT.
 18. The method of claim 16,further comprising a step of receiving (210 c) additional static radioparameters (134′) in a message (138) on a Packet Associated ControlChannel (PACCH) (140).